SOLUTION: From an original group of boys and girls, twenty girls leave. There are then left two boys for each girl. After this, sixty boys leave. There are then two girls for each boy.The nu

Question 280051: From an original group of boys and girls, twenty girls leave. There are then left two boys for each girl. After this, sixty boys leave. There are then two girls for each boy.The number of girls in the original group was:
(A) 81 (B) 72 (C) 68 (D) 60 (E) 50
Answer by josmiceli(19441) (Show Source): You can put this solution on YOUR website!
Let = original number of girls
Let = original number of boys
given:
Initially, there are:
in the group
20 girls leave
in the group
(1)
Then boys leave
in the group
(2)
(1) and (2) are 2 equations with 2 unknowns, so
it's solvable
(1)
(1)
(1)
(2)
(2)
(2)
Multiply both sides of (1) by and add equations
(1)
(2)

The number of girls in the original group was 60
check answer:
(1)

(2)
(2)

OK
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