Question

a positive integer n is called special if n is divisible by 4, N+1 is divisible by 5 and n+2 is divisible by 6. how many special integers smaller than 1000 are there?​

Answer 1

17

Explanation:

these positive integers are :

4, 64, 124, 184 ... , 964

964 = 4 + (n-1) (60)

964 = 4 + 60n -60

964 = 60n -56

60n = 1020

n = 1020/60

n = 17

so, the number of special integers smaller than 1000 are = 17