Question

C. 12
D. 13
36. 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
cach boy. Find the number of boys in the be-
ginning
A 40
B. 50
C. 60
D. 30
class
If 4 students​

Answer 1

Answer:

No of boys in beginning=50 (B)

Step-by-step explanation:

let their are x boys and y girls

now 15 girl leaves then there are  left 2 boys for each girl.

x=2(y-15)

x-2y=-30..................(1)

Now 45 boys leave then 5 girls for each boy

boys=x-45

girls=y-15

so 5(x-45)=y-15

5x-225=y-15

5x-y=210

or 10x-2y=420....................(2)

subtract (1) from(2)

9x=450

x=50

In (1) plug value of x

50-2y=-30

2y=80

y=40

No of boys in beginning=50