Question

How many 3 digit numbers can be formed by 0; 2; 4; 5; 7 such that the digits are divisible by 5 and the repetition of any number is not allowed

Answer 1

Three digit number to be divisible by 5 , the last digit should be 5 or 0

_ _ _5

Two remaining places can be filled in 4×3=12

_ _ _0

Two remaining places can be filled in 3×3=9 (0 cannot be filled in the first place, it will become 2 digit number).

Total =12+9=21