One day, 90 students were travelling in a bus and the ratio of the number of boys to that of girls was 2 : 1. The next day, the number of students remained the same, but the ratio of the number of boys to that of girls became 3 : 2. What was the difference between the numbers of boys travelling in the bus on both the days?
Show answer & explanation
Correct answer: A
Explanation
The correct answer is option 1 i.e. 6.
Total number of students = 90
The ratio of the number of boys to that of girls on the first day = 2 : 1
Number of boys = 90 × (2 ÷ 3) = 60
Number of girls = 90 - 60 = 30
The ratio of the number of boys to that of girls on the second day = 3 : 2
Number of boys = 90 × (3 ÷ 5) = 54
Number of girls = 90 - 54 = 36
The difference between the numbers of boys travelling in the bus on both days = 60 - 54 = 6