Question

last year, mary planted 10 flower beds and used 8 bags of soil. this year, she will plant 5 flower beds. mary wants to know how many bags of soil she will use.
this year | last year
flower beds | 5 | 10
bags of soil | | 8

Explanation:

Step1: Set up proportion

Let \( x \) be the bags of soil this year. The ratio of flower beds to bags of soil should be constant. So, \(\frac{10}{6}=\frac{5}{x}\).

Step2: Cross - multiply

Cross - multiplying gives \( 10x = 6\times5 \).

Step3: Solve for \( x \)

Simplify the right - hand side: \( 10x=30 \). Then divide both sides by 10: \( x = \frac{30}{10}=3 \).

Answer:

3