7th Grade Unit 5 Review

Ratios

100

Write the ratio of sinks to walls in the classroom:

3:1

200

The ratio of blue to red marbles in the bag was 5 to 2. The ratio of red marbles to green marbles was 2 to 3. What is the ratio of green marbles to blue marbles?

3:5

300

The ratio of sugar to flour is 1 teaspoon: 3 teaspoons. If you need to make 2.5 times the recipe, how much flour do you need?

7.5 teaspoons

400

The cost of a 15 gallon tank of gas is $45. What is the cost of 10 gallons of gas?

$30

500

The cost of 12 oz of steak is $15. What is the cost for 20 oz?

$25

Rates/Unit Rates

100

Find the unit rate:

240 miles on 15 gallons

16 miles per 1 gallon

200

Find the unit rate:

25 trips over 10 months

2.5 trips per 1 month

300

Tell whether the rates are equivalent: 

60 feet for every 8 months

45 feet for every 1/2 year

Yes

400

Tell whether the rates are equivalent:

80 miles per 4 hours

120 miles per 260 minutes

No

500

Which is the cheaper buy?

30" TV for $210

50" TV for $340

30" TV: $7/inch

50" TV: $6.80/inch

Solving a Proportion

100

Tell whether the ratios form a proportion:

7 inches in 9 hours

42 inches in 54 hours

Yes

200

Tell whether the ratios form a proportion:

385 calories in 3.5 servings

300 calories in 3 servings

No

300

Solve the proportion:

8/5=n/15

N = 24

400

Solve the proportion:

3/4=v/14

V = 10.5

500

Solve the proportion:

4/(k+3)=8/14

K = 4

Identifying Proportional Relationships

100

What variable represents the constant of proportionality and represents the multiplicative relationship between 2 quantities

K

200

When graphed, how can you tell a ratio is proportional? (2 things)

1) Graph makes a line

2) Goes through the origin

300

Tell whether x and y are proportional:

X: 0, 3, 6, 9

Y: 0, 1, 2, 3

Yes; makes a line and passes through the origin

400

Tell whether x and y are proportional:

X: 1, 2, 3, 4

Y: -1, 0, 1, 2

No, does not pass through the origin

500

A graph shows the area 'y' (in square feet) that a power paint sprayer can paint in 'x' minutes. The constant of proportionality is 20. Find the area painted in 8 minutes:

160 square feet

Scale Drawings

100

What is a proportional, 2 dimensional drawing of an object?

Scale Drawing

200

What is a proportional, 3 dimensional model of an object?

Scale Model

300

The scale of a given drawing is 1 inch: 5 feet. If the building is going to be 75 feet tall, how long should the drawing be on the paper?

15 inches

400

The scale of a given drawing is 1 cm: 2 yards. If the drawing shows the height of a building as 15 cm, how tall is the building in FEET?

90 feet

500

A new NFL stadium is going to be built. It will be 800 feet long and 300 feet wide. What would the dimensions of the stadium be on paper if the scale is 1 cm: 20 feet?

40 cm by 15 cm