Question

solve how many three digit numbers are divisible by 5​

Answer 1

100,105,.....,995

d = 5

a1= 100

an = a+(n-1)d

995 = 100 +(n-1)5

995-100 = (n-1)5

895/5 = (n-1)

179+1=n

n = 180

so the 180 three digits numbers are divisible by 5