Question

A bag contains red and blue counters in the ratio 3:5. There are 90 red counters in the bag. What is the total number of counters in the bag?​

Answer 1

Answer is 240 total counters in the bag

Step by step

3:5 is the same as fraction 3/5

We can cross multiply to find the unknown
3 red / 5 blue = 90 red / x blue

3/5 = 90/x

Cross multiply
3 * x and 5 * 90

3x = 450
Divide both sides by 3 to solve for x

3/3 x = 450/3
Simplify

X = 150 blue counters

150 blue + 90 red = 240 total counters

To check your work,
90 red / 150 blue = 90/150
So
90/150 simplified = 3/5 = 3:5
Problem solved!

Answer 2

The total number of counters in the bag is 150.

Explanation:

There are 90 red counters and the ratio of red to blue is 3:5, which means that for every 3 red counters there are 5 blue counters. Thus, 90 red counters would mean that there are 5/3 times as many blue counters, or 150/3 = 50 blue counters. Therefore, 90 red counters + 50 blue counters = 150 counters in total.