Question

How many 4 digit numbers abcd exist such that a is odd, b is divisible by 3, c is even, and d is prime?

Answer 1

'a' is odd, 5 choices
'b' is divisible by 3, 3 choices
'c' is even , 4 choices
'd' is prime, 4 choices.

So what is 5x3x4x4 ?

Answer 2

Poli

Answer 3

The answer is 5×4×5×4=400
Since a={1,3,5,7,9}
B={0,3,6,9}
C={0,2,4,6,8}
D={2,3,5,7}

Answer 4

The answer is 400