Question

The average age of 40 students of a class is 18 years. when 20 new students are admitted to the same class,the average age of the class is increased by 6 months. the average age of newly admitted students is

Answer 1

average age of 40 students = 18 years = 216 months.

total age of 40 students = 40*18 = 720 years = 8640 months.

when 20 students admitted,

the average age of 60 students = 18.5 years = 222 months.

and the total age of the 60 students = 1110 years = 13320 months.

then, total age of 20 students = 1110 - 720 = 390 years = 4680 months.

average age of 20 students = 390/20 years, or 4680/20 months

= 19.5 = 19 years 6 months, or 234 months.