Question

you have 20 coins in your coin dish: 4 nickels, 3 dimes, 7 quarters, and 6 pennies. You draw one coin at random, do not replace it, then draw a second coin. Find each probability:

a. You end up with 6 cents
b. You end up with 35 cents
c. You end up with 20 cents

Answer 1

Step-by-step explanation:

a. To get 6 cents, one coin needs to be a nickel and the other coin needs to be a penny.

P = P(nickel then penny) + P(penny then nickel)

P = (4/20) (6/19) + (6/20) (4/19)

P = 12/95

b. To get 35 cents, one coin needs to be a dime and the other coin needs to be a quarter.

P = P(dime then quarter) + P(quarter then dime)

P = (3/20) (7/19) + (7/20) (3/19)

P = 21/190

c. To get 20 cents, both coins need to be dimes.

P = P(dime then dime)

P = (3/20) (2/19)

P = 3/190