Question

How many integers in the interval [100, 999] are not divisible by 14?

Answer 1

69

Explanation:

Numbers between 100 to 999 which are divided by 13

104,117,130............................988 .

So a=104, d=13 and,an=988

an=a+(n−1)d

988=104+(n−1)⋅13

88413+1=n

n=69