Question

₹ 776 is divided among 300 students (boys and girls). Each boy gets ₹ 2.40 and each girl gets ₹ 2.80. Find the number of girls.

• A. 130
• B. 140
• C. 110
• D. 120

Hint:

Two linear conditions (headcount and total money) \(⇒\) solve by substitution after clearing decimals.

Answer 1

The Correct Option is B

Let boys \(=B\), girls \(=G\). Then \(B+G=300\) and \(2.4B+2.8G=776\).
Multiply by 10: \(24B+28G=7760⇒ 6B+7G=1940\).
Using \(B=300-G\): \(6(300-G)+7G=1940⇒ 1800-G=1940⇒ G=140\).
\[ \boxed{140} \]