Question

find the average of first 7 multiples of 8 is average multiple of 8

Answer 1

a=8
d=8
n=7
sn=n/2 (2a+(n-1)d)
sn=7/2 (2×8+(7-1)8)
sn=7/2 (16+48)
sn=7/2 (64)
sn=7×32

average = total sum /2
average =7×32/2
average =7 × 16
average of first seven multiples of 8 = 112