Question

No.of positive numbers less than 1000,the sum of integer should divisible by 7 and number itself divisible by 3

Answer 1

Answer:

1. How many positive integers less than 1000 have the property that the sum of the digits of each such number is divisible by 7 and the number itself is divisible by 3? Answer (28) Sol. Sum of the digits is divisible by 7 and number itself is divisible by 3 ∴ x + y + z = 21, x, y, z are digits 0, 1, 2, ...., 9.