Multiple choice

A group of students went to a restaurant to have lunch. On an average, each boy contributed Rs. 190 while each girl contributed Rs. 10. If the average contribution per student was Rs. 70, Find the ratio of boys and girls.

  1. 1 : 2

  2. 2 : 1

  3. 3 : 1

  4. None of these
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Let B be boys, G be girls. (190B + 10G) / (B + G) = 70. 190B + 10G = 70B + 70G. 120B = 60G. G/B = 2/1. Ratio B:G = 1:2.

AI explanation

Using the alligation method, the ratio of boys to girls is determined by the differences between their individual averages and the overall average. The ratio of boys is 70 minus 10, which is 60, and the ratio of girls is 190 minus 70, which is 120. Simplifying the ratio 60 to 120 by dividing both sides by 60 gives the final ratio of boys to girls as 1 to 2.

Keep practicing — related questions