Solving Percent Problems
Classwork
Question1
• John, Gary and Melissa played a computer
game for a total of 3 hours. If John played the
game for 28% of the total time, and Gary
played the game for 52% of the total time,
how many minutes did Melissa play the
game?
Question 2
• Carla paid $24 for slacks that were on sale. If
the original price of the slacks was $32, what
was the percent discount?
Question 3
After a 20% increase, the price of a share of a
computer stock is $78.00. What was the
original price of a share of the computer
stock?
Question 4
• In a factory that manufactures light bulbs,
0.04% of the bulbs manufactured are
defective. What is the minimum number of
bulbs manufactured for which you would
expect to find one defective light bulb?
Question 5
On January 1, Mr. Warner and his son jointly invest
a sum of money at an annual rate of 6 ¾ %. On
January 1 of the following year, their total
investment is worth $5978. If Mr. Warner
invested $4,500 of his own money, how much did
his son invest?
Question 6
• If the length of each side of a square is
increased by 10%, by what percent does the
area of the square increase? (Hint: draw a
diagram)
Question 7
• Nine hundred students were asked whether they
thought their school should have a dress code. A
circle graph was constructed to show the results.
The central angles for two of the three sectors are
shown in the accompanying diagram. What is the
number of students who felt that school should have
a dress code?
Question 8
In bowling leagues, some players are awarded
extra points called their “handicap.” The
handicap in Anthony’s league is 80% of the
difference between 200 and the bowler’s
average. In Anthony’s handicap is 44, what is
Anthony’s bowling average?
Question 9
In a town election, candidates A and B were
running for mayor. There were 30,500 people
eligible to cote, and 80% of them actually
voted. Candidate A received 6100 votes.
What percent of the votes cast did candidate
B received?
Question 10
A class consists of 14 boys and 19 girls. On a
certain day, all the boys were present, and
some girls were absent. If the girls made up
only 30% of the class attendance on that day,
how many girls were absent?
Question 11
• A basketball player made 9 foul shots, which is
75% of the number he attempted. The coach
tells the same player to keep making foul
shots until the total number of foul shots
made is 90% of the total number attempted.
What is the minimum number of additional
foul shots the basketball player needs to
make?
Question 12
• Walter is a waiter at the Towne Diner. He
earns a daily wage of $50, plus tips that are
equal to 15% of the total cost of the dinners
he serves. On Tuesday he earned $170. What
was the total cost of the dinners he served on
Tuesday?
Question 13
• Sue bought a beach chair on sale for 50% off
the original price. The store charged her 10%
tax, and her final cost was $22.00. What was
the original price of the beach chair?
Question 14
When Raymond was on a diet, his weight gain w in
pounds after x days on the diet could be
approximated by the formula w = 240 – 0.6x.
A) After how many days on the diet did Raymond’s
weight drop to 210 pounds?
B) What percent of his original weight did Raymond
lose after 30 days on the diet?
Question 15
A student answered 50% of the questions on a
test correctly. If she answered 10 questions
correctly out of the first 12 and 25% of the
remaining questions correctly, how many
questions were on the test?
Question 16
A painting that regularly sells for $55 is on sale for 20%
off. The sales tax on the painting is 7%. What is the
final cost?
Does the final total cost of the painting depend on
whether the salesperson deducts the discount before
adding the sales tax or takes the discount after
computing the sum of the original price and the sales
tax on $55? Justify your answer.
Question 17
Keysha wants to tile the floor shown in the accompanying
diagram. If each tile measures 1 foot by 1 foot and costs
$2.99, what will be the total cost, including an 8% sales tax,
for tiling the floor?
3 ft
10ft
4ft
7ft