Question

There are10 boxes in a grab bag. Seven of themcontains $20

bills.A contest winner gets to pick two boxesfrom the grab bag.
What are the probability of getting
two $20 bills?

Answer 1

7/15

Explanation:

7 boxes out of 10 contain $20. Therefore 3 boxes do not have $20 bills.

The probability of picking a bag with a $20 bill

= 7/10

The probability of picking another bag with $20 bill

= (7-1)/(10-1)

= 6/9

The probability of getting two $20 bills.

= 7/10 × 6/9

= 42/90

= 7/15