Candy bars are on sale at the grocery, buy 3 get 1 free. There are only 15 candy bars left (5 dark chocolate and 10 white chocolate). A shopper randomly grabs 10 bars. What is the probability the shopper will grab exactly 3 white chocolate bars?  Select the correct option:
A) 7/9
B) 3/5
C) 40/91
D) 3/7
E) 7/120
Combination Probability Formula: nCr = n!/[r!(n-r)!]   Total possible, select 4 bars from 15 bars = 15C4 = 15!/[4!(15 - 4)!] = 1,365.   To have 3 white there must be 1 dark, select 1 dark from 5 = 5C1 = 5.   And, select 3 white from 10 = 10C3 = 120.   3 white and 1 dark = (5)(120) = 600   Probability = (number outcomes favorable)/(total number outcomes) = 600/1,365 = 40/91   Answer: 40/91
<result>C</result>
Candy bars are on sale at the grocery, buy 3 get 1 free. There are only 15 candy bars left (5 dark chocolate and 10 white chocolate). A shopper randomly grabs 10 bars. What is the probability the shopper will grab exactly 3 white chocolate bars?