The average age of students of a class is 15.8 yr. The average age of boys in the class is 16.4 yr and that of the girls is 15.4 year. Find out the ratio of the number of boys to the number of girls in the class


A) 3 : 1

B) 5 : 2

C) 2 : 3

D) 3 : 7

Correct Answer:
C) 2 : 3

Description for Correct answer:
Girls - 15. 4
Boys - 16.4
Average = 15.8

Girls = 16.4 - 15.8 = 0.6
Boys = 15.8 - 15.4 = 0.4

Clearly, Boys : Girls = 0.4 : 0.6 = 2 : 3

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