Question

The first 15 multiples of 5 are separated into three sets X, Y and Z each comprising of 5 numbers. Find the maximum possible sum of medians of three sets.

Answer 1

first multiple of 5 is 5

15 th multiple is 75

now lets use arithmetic progression

common difference d is 5

first term a=5

formula:

sum=n/2[first term + last term]

n=15

sum=15/2[75+5]

=15 x 40

=600

check it

5+10+15+20+25+30+35+40+45+50+55+60+65+70+75=600