Question

Sum of all numbers from 4 to 120 divisible by 3

Answer 1

Step-by-step explanation:

6,9,12,15,.......120

an=a+n-1×d

120=6+3n-3

117/3=n

n=39

sum of all numbers=sn=n/2(a+l)

sn=39/2(6+120)

sn=39×63