Consider a basket that contains 15 slips of paper numbered 1 to 15 . Two slips of paper are drawn at random. What is the probability of drawing 2 even numbers?

Question

anonymous · Answer

So how many even numbers are there from 1-15?

anonymous · Answer

7

nurali · Answer

A combination of 2 slips out of 15 can be drawn in 15nCr2 or 105 ways. Two of the 7 even numbers could be chosen in 7nCr2 or 21 ways. 

The probability of pulling 2 evens out is 21/105 = 1/5

agent0smith · Answer

This is similar to the last one - think of it as pulling out two even numbers in a row. 

The first will be 7/15 (total slips of paper is 15). Find the probability of pulling out another even number.