How many numbers from 11 to 50 are there which are exactly divisible by 7 but not by 3 ?
Only 4 they are 14 28 35 49
The required numbers are 14, 28, 35, 49. Clearly, there are four such numbers.
How many 3-digit numbers can be formed from the digits 2, 3, 5, 6, 7 and 0, which are divisible by 5 and none of the digits is repeated?
