Correct Answer - Option 4 : 17 ∶ 26
Given:
Girls ∶ Boys = 5 ∶ 8
Total strength = 11700
New boys joined = 1300
Calculation:
Let assume that number of girls be 5x
The number of boys be 8x
⇒ Total strength of school = 5x + 8x = 13x
⇒ Number of girls in the school = 11700 × 5x/13x = 4500
⇒ Number of boys in the school = 11700 × 8x/13x = 7200
New strength of school = 11700 + 1300 = 13000
Number of boys in the school after new joinings = 7200 + 1300 = 8500
Number of boys ∶ Total strength
⇒ 8500 ∶ 13000
⇒ 17 ∶ 26
∴ The ratio of boys to total students = 17 ∶ 26
The correct option is 4 i.e. 17 ∶ 26