Hello, sri340!

With a little Thought, the solution is quite straight forward.The digits 2, 3, 4, 7 and 8 are each used once to form a

five-digit number.

What is the probability that the tens digit is odd and the number is divisible by 4?

We have a 5-digit number and its tens digit is odd.

There are only 2 choices for the odd digit.

The tens digit is 3: . _ _ _ 3 _

To be divisible by 4, the units digit must be 2.

And the other 3 digits can be placed in ways.

The tens digit is 7:_ _ _ 7 _

To be divisible by 4, the units digit must be 2.

And the other 3 digits can be placed in ways.

Hence, there are: . such numbers.

Since there are possible 5-digit numbers,

. . The probabiity is: .