Example 5.67 from Prealgebra, 5.6 Ratios and Rate

Ratios and Rate: example 5.67

Paul is shopping for laundry detergent. At the grocery store, the liquid detergent is priced at $$14.99$ for $64$ loads of laundry and the same brand of powder detergent is priced at $$15.99$ for $80$ loads.

Which is the better buy, the liquid or the powder detergent?

Work it out on paper first. Then open the solution one step at a time, and stop as soon as you can finish on your own.

Your turn

The book's Try It right after this example: same idea, new numbers. Only the answer is given.

Find each unit price and then determine the better buy. Round to the nearest cent if necessary.

Brand A Storage Bags, $$4.59$ for $40$ count, or Brand B Storage Bags, $$3.99$ for $30$ count

How did it go?

	Liquid	Powder
Write as a rate.	$\frac{$14.99}{64 loads}$	$\frac{$15.99}{80 loads}$
Find the unit price.	$\frac{$0.234…}{1 load}$	$\frac{$0.199…}{1 load}$
Round to the nearest cent.	$\begin{matrix} $0.23/load \\ (23 cents per load.) \end{matrix}$	$\begin{matrix} $0.20/load \\ (20 cents per load) \end{matrix}$

	Liquid	Powder
Write as a rate.	$\frac{$14.99}{64 loads}$	$\frac{$15.99}{80 loads}$
Find the unit price.	$\frac{$0.234…}{1 load}$	$\frac{$0.199…}{1 load}$
Round to the nearest cent.	$\begin{matrix} $0.23/load \\ (23 cents per load.) \end{matrix}$	$\begin{matrix} $0.20/load \\ (20 cents per load) \end{matrix}$

Ratios and Rate: example 5.67

Solution

Your turn

Ratios and Rate: example 5.67

Solution

Your turn