PROBABILITY Worksheet Answers

1.  If you roll a standard six – sided die, what is the probability of rolling :

a)  5 ? P5= 16

b)  3 or a 6 ? P3 or 6 = 26 or 13

c)  an odd number ? P odd # = 36 or 12

2.  Using a standard 52 – card deck, what is the probability of drawing :

a)  a king ? Pking= 452 or 113

b)  a red 6 ? P red 6 = 252 or 126

c)  A black ace or a queen ? P blak ace or Q = 652 or 326

3.  Virginia has a bag with 3 red marbles, 4 blue marbles, and 3 green marbles. If she draws two marbles independently with replacement, what is the probability that she will draw a green marble on the first try, and a red marble on the second try?

3+4+3=10 marbles

Pgreen=310 and Pred=310

P green , red=Pgren∙Pred=310∙310= 9100

4.  Brett has 4 black pens, 3 blue pens, and 7 purple pens in his back pack. If he randomly picks a pen to do his homework, what is the probability that he will pick a blue or purple pen?

4+3+7=14 pens

Pblue=314 Ppurple=714

P blue , purple =P blue∙Ppurple=314∙714=328

5.  Julie has 3 butterscotch, 5 cinnamon, 4 peppermint, and 2 grape candies in her bag. If she lets two friend randomly pick a piece of candy to eat, what is the probability that both friends will choose a peppermint candy?

3+5+4+2=15 candies

P 1st pick peppermint =415

P 2nd pick peppermint =314

P 2 peppermints no replacement =415∙314=235

6.  Kenny has 2 yellow gumballs, 6 red gumballs, 5 purple gumballs, and 3 pink gumballs in a paper bag. What is the probability of drawing a yellow gumball on the first try and then a pink gumball on the second try without replacement?

2+6+5+3=16 gumballs

Pyellow=216 Ppink=315

P yellow , pink =216∙315=140