Problem Statement
In a class the ratio of boys to girls is 7:5. If 6 boys leave and 6 girls join, the ratio becomes 1:1. Find the original number of students.
Explanation
Let boys be seven k and girls be five k. After change: boys seven k minus six equals girls five k plus six. So seven k minus six equals five k plus six ⇒ two k equals twelve ⇒ k equals six. Total is twelve k equals seventy two? Wait total is boys plus girls equals twelve k equals seventy two. But check with new numbers: Boys 42−6=36, Girls 30+6=36 fine. The options include 72. Choose seventy two.
Code Solution
SolutionRead Only
7k−6 = 5k+6 ⇒ 2k=12 ⇒ k=6 ⇒ total=12k=72
