Question

How many numbers are between 200 and 500 which are completely divisible by 7

Answer 1

203, 210,217,........497
a =203 , d = 7 , nth term = 497
nth = a+ (n- 1) d
497 = 203 + (n- 1) 7
497 - 203 = (n-1)7
294/7 = (n-1)
42 = n- 1
n = 43