7th Grade Math

172 Rational Numbers

ALGEBRA Evaluate each expression if g = - _^1

6

, h = _^1

2

, and j = 3 _^2

3

. Write in
simplest form.
37. j ÷ h 38. g ÷ j 39. 3 g ÷ h 40. h ÷ ( _^1
2
j)

For each of the following, write your answers in simplest form.

(^4141) SHOPPING A supermarket sells pretzels in ^3
4 -ounce snack-sized bags or
12 ^12 -ounce regular-sized bags. How many times larger is the regular-sized
bag than the snack-sized bag?

42. MEASUREMENT A recipe calls for 2 ^2
    3
    cups of brown sugar and ^2
    3
    cup of
    confectioner’s sugar. How many times greater is the number of cups of
    brown sugar in the recipe than of confectioner’s sugar?


43. SCHOOL The table shows the number of hours Weekly Study Hours

Hours Fraction ofStudents

None _ 501

1–2 _ 252

3–5 _^1150

6–7 _ 10017

8–10 _^15

Over 10 _ 10019

Not sure _ 253

students spend studying each week.

a. How many times greater was the number

of students who spent over 10 hours each

week studying than those who spent only

1–2 hours each week studying?

b. How many times greater was the number

of students who spent 3 or more hours each

week studying than those who spent less

than 3 hours each week studying?

44. SCHOOL SUPPLIES Tara bought a dozen folders. She took _^1
    3
    of the dozen
    and then divided the remaining folders equally among her four friends.
    What fraction of the dozen did each of her four friends receive and how
    many folders was this per person?


45. WEATHER A meteorologist has issued a thunderstorm warning. So far, the
    storm has traveled 35 miles in _^12 hour. If it is currently 5:00 p.m. and the
    storm is 105 miles away from you, at what time will the storm reach you?
    Explain how you solved the problem.


46. MULTIPLE REPRESENTATIONS Jorge recorded the Student Miles

Lucia 5 1 _ 2

Lon 8 2 _ 3

Sam 12 _^56

Jamal 2 7 _ 9

Thuy 17 _^1318

distance that five of his friends live from his house

on the chart that is shown.

a. NUMBERS Thuy lives about how many times

farther away than Jamal?

b. ALGEBRA Write and solve an equation to find the

mean number of miles that Jorge’s friends live

from his house. Write your answer in simplest form.

c. MODEL Draw a bar diagram that can be used to find

how many more miles Lon travels than Lucia to get to Jorge’s house.

Mean

To fi nd the mean of a

data set, fi nd the sum of

the data and then divide

by the number of items in

the data set.

168_173_C3L3_895130.indd 172 12/31/09 12:44 PM