6-1 Ratios and Unit Rates
Write the ratio as a unit rate.
150 miles in 3 hours
(150 mi)/(3h) = 50(mi) /h
Solve the proportion
3/7 = n/28
n = 12
Write each percent as a fraction in the simplest form and as a decimal.
24%
6/25
0.24
Write and solve a proportion.
Find 15% of 48
15/100 = n/48
n = 7.2
Find the percent of change. Tell whether the change is an increase or a decrease.
120 to 90
25% decrease
Write the ratio as a unit rate.
279 Michelle Obamas for 50 states
5.58 Michelle Obamas per state
Solve the proportion using a cross product. Round to the nearest tenth if necessary.
15/a = 30/98
a = 49
Write each percent as a fraction in the simplest form and as a decimal.
0.5%
1/200
0.005
Write and solve an equation.
What percent of 180 is 9?
n * 180 = 9
5%
Find the percent of change. Tell whether the change is an increase or a decrease.
285 to 342
20% increase
Write the ratio as a unit rate.
$9.45 for 5 lb
($9.45)/(5 lb) = ($1.89)/(lb)
Solve the proportion using a cross product. Round to the nearest tenth if necessary.
53/2 = 18/x
x = 0.7
Write each number as a percent. Round to the nearest tenth of a percent.
120/50
240%
Write and solve a proportion.
125% of y is 100. What is y?
125/100 = 100/y
y = 80
A shop bought a hat for $5 and then marked it up by 75%. Find the selling price.
$8.75
A 10-oz box of cereal costs $2.79. A 13-oz box of the same cereal costs $3.99. Find the unit cost of each item and determine which is the better buy.
$0.28/oz, $0.31/oz
The 10-oz size is the better buy
Solve the proportion using a cross product. Round to the nearest tenth if necessary.
(d-5)/(d+4)=2/3
d = 23
Write each number as a percent. Round to the nearest tenth of a percent.
16/18
88.9%
Write and solve an equation.
Find 68% of 300
n = 0.68 * 300
n = 204
Peaches that are usually priced at $2/lb are on sale for 15% off. Find the sale price.
$1.70/lb