Test_ch07_Practice_w_keyFormE_sp15.docx Spring 2015 | page 1

Directions: Show all work here or on separate paper. (See Key at bottom of document.)

Chapter 7 Form E:

Write fraction notation for the following ratios. Do not simplify:

1. 18 to 24

2. 1.8 to 200

Write fraction notation for the following ratios and simplify:

3. 45 to 60

4. the ratio of length to width of a rectangle with length 0.36 and width 0.21.

5. Mary’s heart beats 41 times in one half (1/2) minute. What is the rate per minute?

6. A leaky hose loses 35 gallons of water in a week. What is the rate in gallons per day?

7. The following table lists prices for various cans of cat food. Find the unit price of each package, rounding to the nearest tenth of a cent per ounce. Then determine which has the lowest unit price.

Coffee
Brand / Size / Price / Unit Price
A / 6 oz. / $1.59
B / 5 oz. / $1.39
C / 8 oz. / $2.09

8. SKIP

Solve for x in 9 and 10: (Cross multiply and solve the equation for x.)

9. ( without equation editor: x/21 = 15/33 )

10. ( without equation editor: 6/x = 3.5/7 )

11. On February 9, 2010, 1 U. S. dollar was worth 7.769 Hong Kong dollars. How much would an item that costs 200 Hong Kong dollars cost in U. S. dollars? Round to nearest cent.

12. Gary’s car traveled 432 mi. on 12 gal of gas. At this rate, how many gallons would be needed to travel 600 mi?

13. On a map, 2 in. represents 60 mi. If two cities are 2.5 in. apart on the map, how far are they apart in reality?

14. SKIP

15. The sides in this pair of triangles are proportion. Find the missing side y of the smaller triangle.

Given info:

The ratio of the left side to the bottom side of the larger triangle is 4 to 5

The ratio of the left side to the bottom side of the smaller triangle is 3 to y

43

5 y

KEY:

1. 18/24

2. 1.8/200

3. 45/60 reduces to 3/4

Reduce by dividing out 15 to top and bottom.

4. 0.36/0.21 reduces to 12/7

Reduce by:

(1) multiplying top and bottom by 100 to get 36/21

(2) dividing out 3 to top and bottom.

5. beats per min: 41 / ½ reduces to 82 beats per min.

Solution:

Reduce by division: 41 / ½ means 41 divided by ½

and that means 41 times 2/1, or 41 x 2 = 82. So the answer is 82 beats per min.

6. 35 gal. in 1 week:

Solution:

Gallons/weeks = 35/1 . Note there are 7 days in 1 week, so

Gallons/days = 35/7

And 35/7 = 5 gal per day

7. unit price price/ounce:

1.59/6 = 0.265

1.39/5 = 0.278

2.09/8 = 0.261 – this is the smaller number so best price.

8. skip

9. x/21 = 15/33

or

cross multiply:

33x = 21(15)

33x = 315

x = 9.55 (rounded)

10. 6/x = 3.5/7

or

cross multiply:

3.5x = 6(7)

3.5x = 42

x = 12

11. Use: US $/HK $

1/7.769 = x/200 or

Cross mult:

7.769x = 200

x = 25.7433 = 25.74

12. Use: miles/gallons

432/12 = 600/x or

Cross mult:

432x = 600(12)

432x = 7200

x = 16.666 = 17 gal.

13. Use: inches/miles

2/60 = 2.5/x or

Cross mult:

2x = 60(2.5)

2x = 150.0

x = 75

14. skip

15. Use left side/bottom side of triangle

4/5 = 3/y or

Cross multiply:

4y = 15

y = 15/4 (fraction answer)