Question

how many numbers are there from 700 to 950 which are neither divisible by 3 or 7

Answer 1

series of number which is divisible by 3or7
714,735,756,.....945 a=714, d=21

945=a+(n-1)d
945=714+(n-1)21
945-714=(n-1)21
231=(n-1)21
n-1=231÷21
n-1=11
n=12
numbers between 700 to 950 is 251

numbers are there from 700 to 950 which are neither divisible by 3 or 7 = 251-12=239