<PRE><B>Question 1204798</B>

There were 2 classes A and B. 3/4 of the students in A and 5/8 in B passed a test. An equal number of students in both classes failed the test. If there was a total of 84 passes,what was the total number of students in both classes.


There were 2 classes A and B

Let class A have A students
class B have B students


 3/4 of the students in A and 5/8 in B passed a test.

1/4 A failed in class A and 3/8 B failed in class B

An equal number of students in both classes failed the test.
1/4 A = 3/8 B
8A=12B
divide by 4
2A=3B
2A-3B=0--------------------------------(1)

 there was a total of 84 passes
3/4 A +5/8 B =84
multiply equation by 8

6A +5B =672------------------------------(2)

Multiply (1) by 3 and subtract from (2)

6A +5B =672
6A-9B=0
--------------
14 B = 672
B= 48

2 A = 3B

2A = 3*48
A = 3*48/2= 72

The total number of students in both classes is A+B=72+48=120

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