# Each marble bag sold by tammy's marble company contains 5 blue marbles for every 3 green marbles....

## Question:

Each marble bag sold by tammy's marble company contains 5 blue marbles for every 3 green marbles. if a bag has 21 green marbles, how many blue marbles does it contain?

## Ratio and Proportion

Ratios can be expressed into fractions. When two fractions are equivalent, then the two ratios form a proportion. A proportion may be created by multiplying both the terms of a ratio by a factor called the scale factor.

## Answer and Explanation:

If the ratio of blue to green marble is 5:3, we have:

{eq}\dfrac{5}{3} = \dfrac{b}{21} {/eq}

where b is the number of blue marbles.

Solving for b, we will have:

{eq}\begin{align} \dfrac{5}{3}& = \dfrac{b}{21}\\[0.2cm] \,&\,\Downarrow\\[0.2cm] \dfrac{5}{3}(21)& = b\\[0.2cm] \dfrac{105}{3}&=b\\[0.2cm] b&=35 \end{align} {/eq}

Therefore, there are** 35 blue marbles**.

#### Ask a question

Our experts can answer your tough homework and study questions.

Ask a question Ask a question