Question

a bag of marbles contains 5 red, 10 blue, 3 yellow and 7 green marbles . Lisa chooses one marble at random from the bag. What is the probability of NOT choosing a red marble?

Answer 1

Total marbles = 5 + 10 + 3 + 7 = 25

Total marbles that are not red = 10 + 3 + 7 = 20

P(Not red marble) = 20/25 = 4/5

Answer: 4/5

Answer 2

Hello!

First you have to find how many marbles there are

5 red
10 blue
3 yellow
7 green

Add these up

5 + 10 + 3 + 7 = 25

To find the probability of not choosing a red marble you put the amount of marbles that are not red over the total amount of marbles

20 non-red marbles
25 marbles in total

So the probability is 20/25

This can be simplified to 4/5

The answer is 4/5

Hope this helps!