From a group of boys and girls,15 girls leave.There are then left 2 boys for each girl.After this,45 boys leave.There are then 5 girls for each boy.Find the number of girls in the beginning? Pick:
A) 20
B) 30
C) 40
D) 50
E) 60
15 girls leave,B+(g-15)=0   then,B=2*(g-15)----------------------&gt;&gt;&gt;1   45 boys leave,(b-45)+(g-15)=0   then,(g-15)=5(b-45)   Hence,the number of girls in the beginning are,   5(b-45)-(g-15)=0-------------------&gt;&gt;&gt;2   put 1 in 2, we get,   5(2*(g-15)-45)-(g-15)=0   10g-150-225-g+15=0   9g-360=0   9g=360   g=40   ANSWER:40
<result>C</result>
From a group of boys and girls,15 girls leave.There are then left 2 boys for each girl.After this,45 boys leave.There are then 5 girls for each boy.Find the number of girls in the beginning?