Question

Two black balls and five white balls are placed in a bag. If Amy draws two balls from the bag, what is the probability that they are both white? Please show your work.

Answer 1

2 +5 = 7 total balls.

!st one being white = 5/7

2nd one being white = 4/6 = 2/3

Chance of both being white = 5/7 x 2/3 =  10/21

Answer 2

      first ball                    and              second ball

5 white out of 7 total       x          4 white remaining out of 6 total remaining

       $\frac{5}{7}$                              x               $\frac{4}{6}$

$= \frac{5*4}{7*6} = \frac{20}{42} = \frac{10}{21}$