Mary has six cards whose front sides show the numbers 1,2,3,4,5 and 6. She turns the cards face-down, shuffles the cards until their order is random, then pulls the top two cards off the deck. What is the probability that exactly one of those two cards shows a square number?
+421 Favorable/Possible
Possible=6C2=15
Favorable= 8:
1,2
1,3
1,5
1,6
4,2
4,3
4,5
4,6
8/15
