In Exercises 6—12, use the fact that there are 180 pennies in a pound of pennies, 90
nickels in a pound of nickels, 200 dimes in a pound of dimes, and 80 quarters in a
pound of quarters.
6. John is saving money by placing all of his spare dimes in a bucket. The bucket,
when half full, weighs 2 pounds. When empty the bucket weighed ().2 pound.
When the bucket is full, how much money in dimes will John have?
7. Angela has a bucket that is two-thirds full of quarters and weighs 1.75 pounds.
When empty the bucket weighed 0.25 pound. When the bucket is full, how
much money in quarters will Angela have?
8. Carrie has a bucket of nickels that is one-fourth full and weighs 2.8 pounds.
When empty the bucket weighed 0.3 pound. When the bucket is full, how much
money in nickels will Carrie have?
9. James has ajar weighing 12 pounds that is three-fourth full of pennies. The
empty jar weighed 3.75 pounds. When the jar is full, how much money in
pennies will James have?
10. Emma has one pound of quarters and one pound of dimes. I low much money
does Emilia have in quarters and dimes combined?
11. Josie has 25 pounds of quarters and dimes mixed together. How much money
does Josie have in quarters and dimes combined?
12. Luis has 12 pounds of pennies and nickels mixed together. He knows he has
twice as many pennies as he does nickels. How much money in pennies and
nickels combined does Luis have?
3.2 Challenge Practice
1. Solve the equations 2x + 1 = 3, 2x + 1 = 5, and 2x + 1 = 7, then predict the
solution to 2x+1 = 9. Explain your reasoning
2. Solve the equations 3x + 5 = 8, 3x + 2 = 8, and 3x - 1 = 8, then predict the
solution to 3x-4 = 8. Explain your reasoning
3. Solve the equations x - 5 = 55, 2x -5 = 55, and 3x -5 = 55, then predict the
solution to 4x-5 = 55. Explain your reasoning
4. At the start of a race swimmers are swimming side by side in adjacent lanes of
a pool whose lanes are 25 meters long. One swimmer, swimming ill a rate of 60
meters per minute, pulls ahead of' the other swimmer who is swimming at a
rate of 55 meters per minute. How many minutes pass from the start of the race
to when the two swimmers are once again swimming side by side?
5. Ann misses the school bus in the morning and has to get a ride to school. Her
ride leaves 10 minutes after the school bus passed her bus stop, and arrives at
the school at the same time as the bus arrives. If the distance from Ann's bus
stop to the school is 6 miles and ride traveled at an average speed of 36 miles
per hour, then what was the average speed of the school bus as it traveled from
Ann's bus stop to the school?
6. Two friends, Tom and Cecilia, agree to meet at a park to play tennis. Cecilia
lives 4 miles from the park and leaves her house at noon. Tom lives S miles
from the park and leaves his house 10 minutes after Cecilia leaves her house.
How fast will Tom have to travel to reach the park at the same time as Cecilia
if Cecilia is traveling at 12 miles per hour?