Download Unit 3 PostTest Review Part 1 (answers)

Name:_______Answer Key_________________________________________ Date:________________ Per:_________
Unit 3 Review: Ratios and Proportional Relationships
1. What is a unit rate? Give examples of how unit rates are around you every single day.
Rate that is simplified so that it has a denominator of 1; shopping for a better deal, finding
heart rate, time/distance
2. What does proportional mean? How can you tell if something is proportional?
When two rates are equivalent, a quantity that has a constant ratio; straight line that goes
through the origin and simplifies to a constant unit rate
3. A 36-ounce tin of sardines costs $2.50. Find the unit price of each ounce.
7 cents per ounce
2.50
36
= .07
4. Does the following table represent a proportional relationship? Justify your answer (Hint: Divide y by x. If they are
all the same, they ARE PROPORTIONAL)!
x
y
Yes because it has a constant unit rate
1
2.2
2
4.4
3
6.6
4
8.8
5. Does the following table represent a proportional relationship? Justify your answer (Hint: Divide y by x. If they are
all the same, they ARE PROPORTIONAL)! No because it does not have a constant unit rate
x
y
5
17.5
6
21
6. Determine the constant of proportionality in the table below.
x
y
10
20
11
22
7
24.5
8
32.1
y = 2x
12
24
13
26
7. Using Percent Proportions, solve the following:
a.) 130% of 50
= 65
b.) 85% of 25 =
21.25
c.) 120% of 74 = 88.8
.
d.) 15% of 140
= 0.21
8. On a map, 1 cm represents 20 miles. Find the actual distance between two cities if they are 11.4 cm apart on the
map.
𝑐𝑚
𝑚𝑖
1
20
=
11.4
𝑥
x= 228 miles
9. R2D2 rolled 70 miles in 30 minutes. If he rolled at a constant rate, what is his speed in miles per hour? 140 mph
10. Ms. Lovingood divided a bag of 42 chocolate candies between 2 students. The first student received 3 pieces of
candy for every 4 pieces that the second student received. How many candies did each student receive? 1st
student gets 18 pieces of candy and the 2nd student gets 24 pieces of candy.
11. The actual distance between Atlanta and Augusta is 85 miles.
Determine the scale used on the map at the right if the distance is 5 cm.
85
_____1______ cm: ________17_____ miles
5
12. In Mr. DelCastillo’s math class, 47.5% of the students have completed their math project. Of the remaining students,
60% have completed only half of their math project. If there are 32 students in Mr. DelCastillo’s math class, how
many of these students have completed half of their math project?
About 10 students only completed ½
of their project
13. Earl received a 10.5% commission on his total amount of sales. If his sales total was $150.00, what was Earl’s
commission?
$15.75
14. The graph below shows the relationship between the number of quarts in x gallons.
Explain what the ordered pair (4, 16) represents.
quarts
16 quarts in 4 gallons
gallons
15. There are 2 pitchers of iced tea. The iced tea in the first pitcher was made with 8 tea bags and 2.50 quarts of water.
The iced tea in the second pitcher was made with 10 tea bags and 4 quarts of water. Which pitcher has a higher
concentration of tea? Why? The first pitcher has a higher concentration of tea because the ratio
of tea to water is greater
16. Stereo systems at Joe’s Electronics are discounted 20%. If the tax rate is 7%, how much will a $375 stereo system
from Joe’s Electronics cost? 1st find the discount  $375 – $75 (discount) = $300 then find sales
tax  300 x (.07) = $21 finally add discount price and sales tax to find total  $300 + $21 =
$321.00
17. Chairs are being arranged in rows for an assembly in the school cafeteria. The same number of chairs is in each row.
If there are 304 chairs in 8 rows, write an equation that could be used to determine y, the total number of chairs in x
rows.
y= 38x
18. The ratio of boys to girls at a school dance is 3:4. If 252 students attend the dance, how many are boys?
attended the dance
𝐵𝑜𝑦𝑠
3
𝑇𝑜𝑡𝑎𝑙 # 𝑜𝑓 𝑘𝑖𝑑𝑠 7
=
𝑥
252
 7x = 756 
7𝑥
7
=
756
7
 x = 108 boys
108 boys