Ratios and Proportions Review

Ratios and Proportions Review

Part One

Unit Rates

To find a unit rate, you divide both numbers by the number you want to equal 1.

• Ex. 405 miles in 9 hours

• Ex. 4 packs of batteries is $22.16

Multiple Choice

Lynnette can wash 95 cars in 5 days. How many cars does she wash each day?

• 475 cars per day

• 19 cars per day

• .05 cars per day

• 15 cars per day

Multiple Choice

At the market, 7 apples cost $4.55. What is the cost per apple?

• 1.54 apples per dollar

• 1.54 dollars per apple

• $0.65 per apple

• not here

Unit Rates with Complex Fractions

• To divide fractions: Keep, Change, Flip

• Figure out which fraction you want to equal 1, and divide both numbers by that number

• Ex. It takes 1/6 of a minute to fill 1/3 of a water. How much time will it take to fill 1 entire water bottle?

Multiple Choice

Sasha can mow 3/8 of an acre of grass in 3/4 an hour. How many acres of grass does Sasha mow per hour?

• 2 ac./hr.

• 1/2 ac./hr.

• 9/24 ac./hr.

Multiple Choice

Find the unit rate.

Hannah reads 5/ 8 page in 2/3 minute

• 15/16 pages per minute

• 10/24 pages per minute

• 5/8 pages per minute

• 16/15 pages per minute

Part Two

Percentages in the Real World

To find the percent of a number change the percent to a decimal and multiply

• Tax and tip: Percentages added to the original amount

• Discount: Percentages subtracted from the original amount

• Ex. Sales tax is 4%. You purchased $24.00 worth of items. How much do you pay total?

• Ex. You have a coupon for 25% off. You like an $8.00 t-shirt. How much will it be after discount?

Multiple Choice

A pair of jeans is $45.00. If there is a 6% sales tax at the store, how much would we pay with tax?

• $47.70

• $42.30

• $72.00

• $48.50

Multiple Choice

A $15.00 sweater is on sale for 30% off. If there is a 10% sales tax, how much would you pay after tax and discounts?

• $14.00

• $12.00

• $16.00

• $13.50

Multiple Choice

There is a coupon for 20% off a plain white t-shirt that costs $12.00. There is another coupon for $3.00 off any item that can be used for the $12.00 t-shirt. Which coupon would give us the best deal?

• 20% off coupon

• They would come out to the same price

• $3.00 off coupon

Part Three

Equivalent Ratios and Proportions

Equivalent Ratios

• To determine if 2 ratios are equivalent, see if you can multiply or divide both sides of the first ratio to get the second ratio or cross multiply

• Ex. Does 2/3 = 10/15?

• Ex. Does 6:7 = 60: 70?

• Ex. Does 2/8 = 3/12?

• Ex. Solve for x: 1/4 = 5/x

Multiple Choice

Are the ratios  $\frac{4}{1}$  and  $\frac{20}{5}$   equivalent?

• No

• Yes

Multiple Choice

• 7

• 8

• 9

• 10

Multiple Choice

The ratio of girls to boys at basketball practice is 2:3. If there are 12 girls at practice then how many boys are there?

• 15

• 18

• 20

• 21

More Practice

Multiple Choice

Alicia drove at a constant speed and traveled 182.4 miles in 3 hours. What is her rate in miles per hour?

• 60.8 miles per hour

• 547.2 miles per hour

• 56 miles per hour

Multiple Choice

The ratio of 6th graders to 7th graders at a basketball game is 4:1. If there are eight 7th graders, how many 6th graders are there?

• 28

• 16

• 8

• 32