Answer:
The perfect square lockers are the only ones left open.
Step-by-step explanation:
Here is a legit link to an explanation of this old puzzle problem!
https://36university.com/act-math-locker-problem-solution/
Quoting from that page:
Method 2: Who Touches Which Lockers
Identifying which students touch which lockers is a little less of a brute-force approach and would likely have gotten you to the solution a little more quickly.
Here’s what I mean:
Consider locker #1. The only student who touches locker #1 is student #1. Student 1 opens the locker, and since no one else touches it, it will be left open at the end.
Consider locker #2. Student 1 opens the locker, and student 2 closes it. No one else touches the locker, so it will be closed.
Consider locker #10. Students 1 opens the locker. Student 2 closes it. Students 3 and 4 skip right by it. Student 5 opens it. Students 6, 7, 8, and 9 skip right by it. And student 10 closes it. Locker #10 will be closed.
Mental Milestone 1: After looking at several lockers, you should notice that lockers are only changed by student numbers that are factors of the locker number. In other words, locker 12 is changed by students 1, 2, 3, 4, 6, and 12.
Mental Milestone 2: You should also have noticed that factors always come in pairs. This means that for every student who opens a locker, there is another student who closes it. For locker #12, student 1 opens it, but student 12 closes it later. Student 2 opens it, but student 6 closes it later. Student 3 opens it, but student 4 closes it later.
By this logic, every locker would be closed.
But there are exceptions!
Consider locker #25. Student 1 opens it. Student 5 closes it. Student 25 opens it. The locker will be left open, but why? In this case, the factors do not come in pairs. One and 25 are a pair, but five times five is also 25. Five only counts as one factor. This causes the open-close pattern to be thrown off. Locker #25 is left open.
Mental Milestone 3: When factors don’t come in pairs, the locker will be left open. And factors don’t come in pairs when numbers are multiplied by themselves. Perfect squares (1, 4, 9, 16, 25, 36, 49, 64, 81, 100,…) are the only numbers whose factors don’t come in pairs because one set of factors, the square root, is multiplied by itself. This means that only perfect square lockers will be left open.
Locker #s 1, 4, 9, 16, 25, 36, 49, 64, 81, and 100 are left open!
pls help me with this:(((((
2: c
Step-by-step explanation:
3: a
by Supplementing each answer Into the equation
Step-by-step explanation:
what don't you understand about this ? did you never solve 2 equations with 2 variables ?
it is really easy. there are 2 main approaches :
1. substitution. you use one of the two equations to express one variable by an expression purely in the other variable. then you use that in the other equation (resulting in one equation with one variable) and solve it. with that result you go back to the other equation and calculate the other variable.
2. equation arithmetic. when the terms of at least one of the variables are similar in both equations, you can multiply (if needed) one or both equations (left and right side !) by a fitting number and then add it subtract one equation from the other, so that you are left with one equation in one variable, which you solve. with that result you go back to any of the original equations and calculate the other variable.
there would be a third option for questions like this :
3. trial and error. simply put the point coordinates as x and y into both equations, and see for what point(s) both remain true.
but in order to show you the methodical approaches, we will use substitution for question 2 and equation arithmetic for question 3.
2)
2x + y = 5
-x + 2y = 5
I use the first equation to transform. and I get
y = 5 - 2x
with that I go into the second equation :
-x + 2(5 - 2x) = 5
-x + 10 - 4x = 5
-5x = -5
x = 1
and with that I get
y = 5 - 2×1 = 5 - 2 = 3
so, C (1, 3) is the right answer.
3)
2x + y = 7
-x + y = 1
let's subtract the second equation from the first :
2x + y = 7
- -x + y = 1
------------------
3x + 0 = 6
3x = 6
x = 2
with that I go into one of the original equations :
-2 + y = 1
y = 3
so, A (2, 3) is the right answer.
kelsey bought a new jackat. the jackat costs $ 150.00 she will pay 7% in sales tax how much money will she pay in sales tax
Answer:
10.50
Step-by-step explanation:
Answer:
she will pay $10.50 in sales tax and $160.50 in total
Step-by-step explanation:
first, find 7% of 150.
150*.07=10.5
add 10.5 to the total
Can you do it?I can’t understand
Answer:
489,162
Step-by-step explanation:
Hope it can help you lovelots
What is the equation for this? please help!!
Answer:
the equation is y=x^2+8
a group can plant 3/4 acres in 1 7/8. What os the unit rate in acres per day? Write your answer in simplest form.
h3elpppp pleaseeeehejejrhegss
Answer:
First is 1, then 2, then 10
Step-by-step explanation:
I think this is right, could be completely wrong but I did blank times 50 equals 50, that is 1. Repeated with all the problems.
if you add 5 to me then divide 7, and add 12 then subtract 7 you get 10 what number am i
Answer:
hii the answer is 30 :D have a nice day
i dont even think i'm right but ok
didn't you just say you got the number 10? i'm guessing the number is 10
Ellie hikes 1/2 of a mile every 10 minutes. How far does she hike in 1 hour?
Answer choices:
3
5
4
6
Answer:
3miles
Step-by-step explanation:
10 minutes is 1/6 of an hour, so in 1 hour ellie would hike 1/2*6=3miles
Answer:
Step-by-step explanation:
There are various ways in which we can solve this problem.
If we're told that Ellie can hike 1/2 mile in 10 minutes, then multiplying both sides of "1/2 mile = 10 minutes" by 6 yields 3 miles in 60 minutes.
Alternatively: "1/2 mile = 10 minutes" becomes "1 mile in 20 minutes" by the same approach. Then, multiplying both sides by 3 yields "3 miles in 60 minutes," or "3 miles in 1 hour."
Solve:
two fifths plus seven fifteenths equals blank
Question 3 options:
thirteen fifteenths
nine fifteenths
nine twentieths
nine fifths
Answer:
[tex]\frac{13}{15}[/tex]
Step-by-step explanation:
[tex]\frac{2}{5}[/tex] + [tex]\frac{7}{15}[/tex] = [tex]\frac{2.3}{5.3}[/tex] + [tex]\frac{7}{15}[/tex] = [tex]\frac{6}{15}[/tex] + [tex]\frac{7}{15}[/tex] = [tex]\frac{13}{15}[/tex]
Answer number 11 to see if your smarter than my students
the awnser 2=2=2=2=22=2=2=2=2=2+0+7867+
What are numbers that add to 50 and subtract to 10
Answer:
30 plus 20 is 50
30 minus 20 is 10
Find -5(-12) + (-15)
With explanation please i forgot how to do it
Answer:
45
Step-by-step explanation:
-5(-12)+(-15)
--> Multiply -5 and -12 to get 60
60-15
--> Subtract 15 from 60 to get 45
Hope this helps you!
The steps for deriving the Quadratic Formula are shown. Which is the BEST choice for the missing reason?
A) simplify
B) divide by a
C) complete the square
D) take the square root of both sides
Answer:
answer choice is B
Step-by-step explanation:
System of equations pls help me
Answer:
x=6 and y=5
Step-by-step explanation:
We can eliminate the "x" variable by adding the two equations to get 6y=30. This means that y=5.
If we plug y=5 back into one of the original equations:
5x+y=35
5x+5=35
5x=30
x=6
-5x+5y=-5
-5x+5(5)=-5
-5x+25=-5
-5x=-30
x=6
Which confirms that x=6 and y=5 are indeed the correct solutions
Answer:
x=6 ,y=5
Step-by-step explanation:
6y=30,y=5
x=6
Need help with this ASAP I’ll mark brainliest
Answer:
B' (3, 1 )
Step-by-step explanation:
Given
A (- 1, 3 ) → A' (- 3, 7 )
x- coordinate goes from - 1 → - 3 , that is - 2
y- coordinate goes from 3 → 7 , that is + 4
Translation rule is (x, y ) → (x - 2, y + 4 ) , then
B (5, - 3 ) → B' (5 - 2, - 3 + 4 ) → B' (3, - 1 )
Find the value of x in the equation below. 5.4=2x
Answer:
x = 2.7
Step-by-step explanation:
5.4 = 2x
2x = 5.4
Divide both sides by 2.
x = 2.7
Answer: x= 2.7
1. Divide 2 on both sides
2. cancel terms who have the same numerator and denominator
Use parallelogram ABCD. What are the values of x and
y?
A
4y-3
B
x=
y =
3x-9
42
D
37
С
Answer:
the value of x is a number but you can say 1 when you are factorising quadratic expression with the terms
Answer:
x=17
y=10
Step-by-step explanation:
3 2/7 divided by 1 1/4
Answer:
92/35
Step-by-step explanation:
⇒ 3 2/7 ÷ 1 1/4
⇒ (3*7 + 2) / 7 ÷ (1*4 + 1) / 4
⇒ 23/7 ÷ 5/4
⇒ 23 * 4 / 7 * 5
⇒ 92/35
The solution of the expression is 2 22/35.
What is Division method?
Division method is used to distributing a group of things into equal parts.
Given that;
The expression is,
3 2/7 divided by 1 1/4
Now, Solve the expression as;
3 2/7 ÷ 1 1/4
23/7 ÷ 5/4
23/7 x 4/5
92/35
2 22/35
Hence, The solution of the expression is 2 22/35.
Learn more about the division method visit:
https://brainly.com/question/28783040
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Dija writes 7x 9 = 63 to find the
number of players on 7 baseball teams. Describe what
each of the factors represents in the multiplication equation.
Answer:
7 represents the number of teams. 9 represents the amount of players on each team. And 63 represents the total number of players.
Step-by-step explanation:
How do the expressions 2q2−3p and 2(p+q)/q compare when p = 8 and q = 4?Drag a symbol into the box to correctly complete the statement.2q2−3p Response area 2(p+q)/q when p = 8 and q = 4.=<>
Answer:
The answer is ">"
Step-by-step explanation:
I took the quiz epicly
Answer:
>
Step-by-step explanation:
identify the construction that the figure represents
Answer:
(b) congruent segments
Step-by-step explanation:
One copies the length of a segment to make congruent segments. This is done by setting the compass radius to the length of the segment to be copied, then marking the segment length on another line using a given point as a center.
_____
Additional comment
The appearance here is that the segments are not actually congruent, so apparently a mistake has been made in the construction. No angles are shown, and there aren't enough points or arcs shown to support a conclusion that some other construction is being attempted.
Pls answer this and explain!
Answer:
Well if you add up all 3 angles in a triangle you’d get 180 degrees as the answer.
So we can. Jus substitute.
For number 19 you can do this
57+x+x+87+50=180
Now combine like terms
194+2x=180
Now solve
x=-7
Now we can subsitute that into angle A
57+ (-7) which is 50
Measure of angle A is 50.
For number 19 it’s the same thing.
9x+14+16x-4+80=180
Now combine like terms
25x+90=180
Solve
25x= 90
x= 3.6
Now subsitue for A
3.6*9+4 which is 36.4
A is 36.4
If the area of the trapezoid shown is 200 square feet, what is the height h of the trapezoid?
Answer:
[tex]\frac{400}{(10\sqrt{2} + 14\sqrt{3}) }= h[/tex] or 10.42 = h
Step-by-step explanation:
The area of a trapezoid is [tex]A = \frac{1}{2}h(b_{1} + b_{2} )[/tex].
[tex]200 = \frac{1}{2}h(10\sqrt{2} + 14\sqrt{3})[/tex]
[tex]400 = { h(10\sqrt{2} + 14\sqrt{3} )[/tex] Multiply both sides by 2
[tex]\frac{400}{(10\sqrt{2} + 14\sqrt{3}) }= h[/tex]
[tex]\frac{400}{38.39} = h[/tex]
10.42 = h
Please help! :0 :0 PLEASEEEEEE
Answer:
i would say either F or G
i guess choose F
Answer:
8
Step-by-step explanation:
how to turn 40/3 into mixed fraction please give correct abs for brainliest..
x =
12
9
6 2/3
help me out please you guys are awesome ^-^
the answer is x = 6 2/3
ok done. Thank to me :>
The mass of a tin of paint is 890 grams, correct to the nearest 10 grams. Workout the upper bound of the total mass of 10 tins of paint.
Answer:
8900
Step-by-step explanation: :þ
Le regioni italiane bagnate dal mare sono un insieme?
Answer:
non so cosa intendi per intero
Step-by-step explanation:
Può essere più preciso?
Solve the question will mark branliest and with an explantion
Answer:
The car loses $5,635 every year. Multiply 24,500 by 23% (0.23)
Which number represents a square root of 3 [cos(pi/2) + i sin (pi/2)]?
===========================================================
Explanation:
We use De Moivre's Theorem. It says that if you started with
[tex]z = r*\left[\cos\left(\theta\right)+i*\sin\left(\theta\right)\right][/tex]
then raising both sides to the nth power leads to
[tex]z^n = r^n*\left[\cos\left(n*\theta\right)+i*\sin\left(n*\theta\right)\right][/tex]
The term out front r is raised to the nth power. We also have copies of n inside the trig functions.
The square root operation undoes the squaring operation, so we'll be dealing with n = 2.
If you were to go through each answer choice, then you'll find that squaring choice B will lead to the original expression given.
[tex]z = \sqrt{3}*\left[\cos\left(\frac{\pi}{4}\right)+i*\sin\left(\frac{\pi}{4}\right)\right]\\\\\\z^2 = (\sqrt{3})^2*\left[\cos\left(2*\frac{\pi}{4}\right)+i*\sin\left(2*\frac{\pi}{4}\right)\right]\\\\\\z^2 = 3*\left[\cos\left(\frac{\pi}{2}\right)+i*\sin\left(\frac{\pi}{2}\right)\right]\\\\\\[/tex]
Note that working this process in reverse means we apply the square root and we'll go from the expression in choice B to the original expression again.
The complex number Z = √3[cosπ/4 + i sinπ/4] represents the complex number √(3[cosπ/2 + i sinπ/2]) after using the De Moivre's theorem option (B) is correct.
What is a complex number?It is defined as the number which can be written as x+iy where x is the real number or real part of the complex number and y is the imaginary part of the complex number and i is the iota which is nothing but a square root of -1.
We have a complex number in the trigonometric form:
Z = √(3[cosπ/2 + i sinπ/2])
It is required to find the square root of the complex number.
To find the square root of the complex number we can use the De Moivre's theorem:
If
Z = r[cosθ + i sinθ]
Zⁿ = rⁿ[cosnθ + i sinnθ]
Using the above theorem:
Z = √3[cos[(1/2)π/2] + i sin[(1/2)π/2]]
Z = √3[cosπ/4 + i sinπ/4]
Thus, the complex number Z = √3[cosπ/4 + i sinπ/4] represents the complex number √(3[cosπ/2 + i sinπ/2]) after using the De Moivre's theorem option (B) is correct.
Learn more about the complex number here:
brainly.com/question/10251853
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