| 1. List all
the possible outcomes of a coin that is tossed three
times. Calculate the probability of: |
| a) 3 tails b) 3 heads c) 2 heads
and 1 tail d) at least 2 heads |
| |
| Answer:
a) 1/8 b) 1/8 c)
3/8 d) 1/2 |
| |
| |
| 2.
Find the probability of drawing a black card in a single
random draw from a well shuffled 52 card deck. |
| |
| Answer:
P(black card) = 26/52 = 1/2 |
| |
| 3. Find the probability of drawing a face
card in a single random draw from a well shuffled deck of
52 cards. |
| |
| Answer:
P(face card) = 12/52 = 3/13 |
| |
| |
| 4.
Find the probability of drawing an ace from a deck of 52
cards in a single draw. |
| |
| Answer:
P(ace) = 4/52 = 1/13 |
| |
| |
| 5.
Find the probability of drawing the ace of spades from a
deck of 52 cards in a single draw. |
| |
| Answer:
P(ace of spades) = 1/52 |
| |
| |
| 6. In
a bag there are 20 marbles numbered from 1 to 20. If a
person selects one at random, what is the probability
that the number printed on the ball will be a prime
number greater than 3. (Note: A prime number is defined
as a number greater than 1 which is divisible only by
itself and 1.) |
| |
| Answer:
P(prime number > 3) = 6/20 = 3/10 |
| |
| |
| 7. If Sam throws two dice at the same time and
then repeats the procedure for a second time, what is the
probability that the two dice add up to 7 in the two
consecutive throws? |
| |
| Answer:
P(AB) = P(A). P(B) => 1/6 . 1/6
= 1/36 |
| |
| |
| 8.
Find the probability that a face card is drawn in the
first draw and an ace on the second draw in two
consecutive draws, without replacement, from a deck of 52
cards. |
| |
| Answer:
P(AB) = P(A) . P(B|A) = 12/52 . 4/51
= 4/221 |
| |
| |
| 9.
Find the probability of drawing a spade in each of two
consecutive draws from a standard deck, without
replacement of the first card. |
| |
| Answer: P(A) = 13/52
= 1/4 P(B|A) = 12/51 =
4/17 P(AB) = 1/4 .
4/17 = 1/17 |
| |
| 10.
What is the probability that on a single random draw from
a deck of 52 cards either a black face card (Jack, Queen,
or King) or a red ace will be drawn? |
| |
| Answer:
P(black face card or red ace) = P(A) + P(B) = 6/52
+ 2/52 = 2/13 |
