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Ratios and proportions

Solve proportions: word problems

Brandi read a total of 9 books over 3 months. If Brandi has read 12 books so far, how many months has she been with her book club? Assume the relationship is directly proportional.

Set up a proportion and solve for n.

$\frac{9\;books}{3\;months}=\frac{12\;books}{n\;months}$

 9n = 12 × 3 Find the cross products 9n = 36 Multiply n = 4 Divide both sides by 9

If Brandi has read 12 books so far, then she has been with her book club for 4 months.

Carol spends 20 hours in a 4-week period practicing her culinary skills. How many hours does she practice in 10 weeks?

Solution: