Question

In a certain bag, the ratio of red to green to blue marbles is 1:2:3 . There are 5 red marbles. How many blue marbles are there?

Answer 1

Answer: 15

Step-by-step explanation

The ratio 1:2:3 refers to the idea we could have: 1 red, 2 green, 3 blue. The order of the colors is important. Follow the order mentioned in the 1st sentence of the instructions. That order being red:green:blue.

Then the instructions mention that there are actually 5 red (instead of 1 red). This means we multiply each part of the ratio by 5

• 1*5 = 5 red
• 2*5 = 10 green
• 3*5 = 15 blue

The ratio 1:2:3 scales up to 5:10:15

We see that there are 15 blue marbles