posted by Dena on .
In a quiz program, 3 questions on sprots, 3 questions on general knowledge, and 4 questions on science are printed separately on 10 cards and placed upside down. John is asked to select 2 cards at random. What is the probability of Joohn selecting 2 questions on science?
Number of ways to select any two of the 10
= C(10,2) = 45
number of ways to select 2 out of the science
= C(4,2) = 6
prob of that event = 6/45 = 2/15