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