Question

Check my answers please?
1. A container holds 15 pennies, 8 nickels, and 10 dimes. You will randomly select two coins without replacement.

Use the tree diagram to answer the following:
How many ways can you select the coins?
9 ways
How many ways can you select exactly 1 nickel?
3 ways
What is the probability that you select 2 pennies?
35/176
What is the probability that you select a dime and then a penny?
25/176

Answer 1

2. The numbers 1 through 50 are written with red marker on slips of paper while the numbers 51 through 100 are written with blue marker on slips of paper. All the papers are put into a bag and shuffled. One card is randomly selected.

a. Find the probability of selecting a number less than 10 or a number written in blue. Show your work.
b. Find the probability of selecting a number written in red or a multiple of 20. Show your work.
Answer:



a. 59%
The chance of pulling a number less than 10 equals 9% and the chance of pulling a blue is 50%. Since the two are mutually exclusive we must then add the two together to get our answer: 59%.

b. 53%
The chance of pulling a red card is 50%, and the chance of pulling a multiple of 20 is 5%. These events are NOT mutually exclusive so we must first add the probabilities to get 55% and then subtract the probability of the events both happening (2/100 or 2%). 55% – 2%=53% which is our final answer.

Answer 2

Am I right? Any and all help is appreciated. I just don't want to get them wrong. Thanks! :)

Answer 3

this sounds wrong
How many ways can you select exactly 1 nickel?
3 ways

Answer 4

Yeah, I was worried about that one...So what would it be instead?

Answer 5

Are the others ok though?

Answer 6

if you make a tree diagram

and count the number of leaves that show only 1 nickel