Tabitha has a deck of cards numbered 1−10. She picks one card, puts it back in the deck and then chooses a second card. What is the probability that she picks an even number and then a 3?

First compute the whole number of the possibilities :
10*9=90.
Compute the number of favorable possibilities:
There is 5 even numbers. Once we pick an even number, 
we pick 5. So the number of the favorable possibilities is 5.
Now we compute the probability like this:
[tex] \frac{5}{90} [/tex]