IBPS SO Prelims Exam Model Paper 7

Given:
Total no. of students in college B = 200
Ratio of boys and girls in college B = 3 : 5
Total no. of students in college D = 500
Ratio of boys and girls in college D = 4 : 1
Calculation:
Number of boys in college B = (

3

8

) × 200
⇒ 3 × 25 = 75
Number of girls in college B = (

5

8

) × 200
⇒ 5 × 25 = 125
Number of boys in college D = (

4

5

) × 500
⇒ 4 × 100 = 400
Number of girls in college D = (

1

5

) × 100
⇒ 1 × 100 = 100
Total no. of boys and girls in college B and D after merger = 200 + 500 = 700
Total no. of boys in college B and D after merger = 75 + 400 = 475
Total no. of girls in college B and D after merger = 125 + 100 = 225
The ratio of boys to girls = 475 ∶ 225
⇒ 19 ∶ 9
∴ The ratio of boys and girls in college B and D after the merger is 19 ∶ 9.