Simple Probability
A bag contains 3 red marbles and 7 blue marbles. You remove a random marble from the bag, record the color and put it back into the bag. Then you remove another marble from the bag and record its color. Solve this.
P(R,B)=
P(R,R)=
P(B,B)=
P(R,B)= 3/10 x 7/10 = 21/100
P(R,R)= 3/10 x 3/10 = 9/100
P(B,B)=7/10 x 7/10 = 49/100
You flip a coin and roll a die at the same time. What is the probability you will flip a head roll a five?
P(tossing a head)= 1/2
P(rolling a 5)= 1/6
P(tossing a head and rolling a 5)= 1/2 x 1/6 = 1/12
A coin is tossed 10 times.
Independent
There are 13 flavors of ice-cream, and 4 different cones. How many different single scoop ice creams can you order?
13 x 4 = 52
Find the probability of getting an odd number less than 5 in a single throw of a die.
Possible outcomes = {1,2,3,4,5,6}
Favorable outcomes = Getting an odd number less than 5 = {1,3}
P(Getting an odd number less than 5) = 2/6 = 1/3
A bag contains 3 red marbles and 7 blue marbles. You remove a random marble from the bag, record the color and you DON'T put it back into the bag. Then you remove another marble from the bag and record its color. Solve this.
P(R,B)=
P(B,R)=
P(B,B)=
P(R,R)=
P(R,B)= 3/10 x 7/9 = 7/80
P(B,R)= 7/10 x 3/9 = 7/30
P(B,B)= 7/10 x 6/9 = 7/15
P(R,R)= 3/10 x 2/9 = 1/15
Choosing two cards from one deck, keeping the first card.
Dependent
Joshua always wears a shirt, pants, socks, and shoes. He owns 4 pairs of socks, 2 pairs of shoes, 5 pairs of pants, and 3 shirts. How many different outfits can John make?
4 x 2 x 5 x 3 = 120
What is the probability to get prime numbers from a roll of a dice, and then getting heads right away from a throw of the coin?
1/2 x 1/2 = 1/4
A bag contains 3 black balls, 2 green balls. Jake picks a ball, then another ball without putting the first one back in the bag, what is the probability of picking two green balls
P(G,G) = 2/5 x 1/4 = 1/10
Picking 5 candies from a bag that has 3 red, 1 yellow, 4 green, and 2 blue candies. And after you pick the candy, you have to eat it right away.
Dependent
There are 4 people A, B, C, and D. If A, B, C, and D have to stand in a straight line, how many different ways are there?
6 x 4 = 24