The ratio of students in Class X to Class Y is 2 : 5. There are 24 more students in Class Y than Class X. How many students must transfer from Class Y to Class X so that both classes have equal number of students?

12 students

Step-by-step explanation:

Let X and Y stand for the number of students in each respective class.

We know:

X/Y = 2/5, and

Y = X+24

We want to find the number of students, x, that when transferred from Y to X, will make the classes equal in size. We can express this as:

(Y-x)/(X+x) = 1

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We can rearrange X/Y = 2/5 to:

X = 2Y/5

The use this value of X in the second equation:

Y = X+24

Y =2Y/5+24

5Y = 2Y + 120

3Y = 120

Y = 40

Since Y = X+24

40 = X + 24

X = 16

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Now we want x, the number of students transferring from Class Y to Class X, to be a value such that X = Y:

(Y-x)=(X+x)

(40-x)=(16+x)

24 = 2x

x = 12

12 students must transfer to the more difficult, very early morning, class.