Correct Answer - Option 1 : 9.5

**Calculation:**

⇒ Let be assume the score of the boy is x and the score of the girl is y.

⇒ According to question,

⇒ (y/30) - (x/20) = 5

⇒ Average of class = (x + y)/50

⇒ Let be assume new score of boys and girls is x' and y' respectively.

⇒ y/30 - y'/30 = 3

⇒ (x' + y')/50 - (x + y)/50 = 2

⇒ y' = y - 90

⇒ By solving we get x' = x + 190

⇒ New average of boys = (x + 190)/20 = x/20 + 9.5

⇒ The average increase by 9.5.

**∴ The required result will be 9.5.**