There are 5 cards numbered 1,2,3,4,5 in a bag. There is also a fair coin that is tossed what is the probility

P(odds,Tails)
I think it is 3/10 but not sure.
Please explain this to me.

you are correct.

3/5 chance for and odd, 1/2 chance for tails.
3/5 * 1/2 = 3/10