How many 3 – digit number can be formed from the digit 2, 3, 5, 6, 7 and 9, which are divisible by 5 and none of the digits is repeated?
Choose the correct choice:
A) 5 B) 10 C) 15 D) 20 E) 25
Solution   Since each desired number is divisible by 5, so we must have 5 at the unit place. So, there is 1 way of doing it.   Tens place can be filled by any of the remaining 5 numbers.   So, there are 5 ways of filling the tens place.   The hundreds place can now be filled by any of the reaming 4 digits. so, there are 4 ways of filling it.   So, Required number of numbers = (1 × 5 × 4) = 20 . Answer 20
<result>D</result>
How many 3 – digit number can be formed from the digit 2, 3, 5, 6, 7 and 9, which are divisible by 5 and none of the digits is repeated?