lesson 14 solving percent problems

Mr. C Chapter 1: Lesson 14: Solving Percent Equations 1

Lesson 14: Solving percent problems Name:________

Date:_________

Percent Equation

Steps

1. Write the percent equation.

2. Identify the rate, base, and percentage.

3. Change the percent to a decimal.

4. Solve the equation for the unknown.

Answers

1) __________

2) __________

3) __________

4) __________

5) __________

6) __________

7) __________

8) __________

Vocabulary

Rate

The number that has the percent sign.

Key word = % simbol

Base

Original amount. It usually follows after the word of.

Key word = of

Percentage

Part of the original amount. It usually follows after the word is.

Key word = is

Example

What is 40% of 70?

Rate * Base = Percentage

40% * 70 = X

0.4 * 70 = X

28 = X

Answer = 28

Practice

Find the percentage (part of the orininal amount).

Problem 1 Problem 2

20% of 150 is what number? 13% of what number is 300?

Problem 3 Problem 4


Problem 5 Problem 6


Problem 7 Problem 8



Lesson 14: Solving percent problems

Percent Equation

Steps





Answers

1) __________

2) __________

3) __________

4) __________

5) __________

6) __________

7) __________

8) __________

9) __________

10) __________

11) __________

12) __________

Example

What percent of 40 is 6?


X * 40 = 6

15%X

0.15X

40

6X

Answer = 15

Practice

Find the rate (percent).

Problem 1 Problem 2

What percent of 20 is 12? What percent of 400 is 60?

Problem 3 Problem 4


Problem 5 Problem 6


Problem 7 Problem 8


Problem 9 Problem 10






Percent Equation

Steps





Answers

1) __________

2) __________

3) __________

4) __________

5) __________

6) __________

7) __________

8) __________

9) __________

10) __________

11) __________

12) __________

Example

22% of what number is 40?

Rate * Base = Percentage Rate * Base = Percentage

22% * X = 40 0.22 * X = 40

182 X

0.22

40X

Answer = 15

Practice

Find the base (original amount).

Problem 1 Problem 2

45% of what number is 12? 60% of what number is 60?

Problem 3 Problem 4


Problem 5 Problem 6


Problem 7 Problem 8








Commision Problems

Steps





Answers

1) __________

2) __________

3) __________

4) __________

5) __________

6) __________

Example

Richard earns a 10% commission on each item that he sells. What is his commision on a sale

of $410?


10% * $410 = X

0.1 * $410 = X

$41 = X Answer = Richard earns $41 of commission on this sale.

Practice

Solve the word problem.

Problem 1

Ruben earns a 15% commission on each item that he sells. What is his commision on a sale

of $900?

Problem 2

Jessica earns a 5% commission on each item that he sells. What is his commision on a sale of

$900?

Problem 3

Melissa earns a 2% commission on each car she sells. What is her commission on a car that

she sells for $22000?

Problem 4

Monica makes money by commission rates. She gets 3% of everything she sells. If Monica

sold $15000 worth of items this month, what is her salary for the month?

Problem 5

Angela earns a 20% commission on each piece of jewelry that she sells. What is her

commission on a necklace that she sells for $495?

Problem 6

Sonia makes money by commission rates. She gets 9.5% of everything she sells. If Sonia

sold $10000 worth of items this month, what is her salary for the month?



Profit Problems

Steps





Answers

1) __________

2) __________

3) __________

4) __________

5) __________

Example

Maria is selling dounats at the Kern County Fair. She earns a profit of 60% on each bag of

dounats that she sells. How much profit did she earn for a week in which she sold $5000

worth of dounats?


60% * $5000 = X

0.60 * $5000 = X

$3000 = X Answer = $3000

Practice

Find the profit.

Problem 1

Zack is selling snowcones at the local park. He earns a profit of 40% on each snowcone that

he sells. How much profit did he earn for a weekend in which he sold $950 worth of

snowcones?

Problem 2

Jose buys computers in bulk for $500 each. He sells them for $950 each. Calculate the profit

on each computer as a percent and as dollar amount?

Problem 3

Janett bought a car for $5000 and sell it for $7800. Calculate the profit that she earn as a

percent and as a dollar amount.

Problem 4

A store has a flat screen TV on sale for $2300. If the store purchases the TV for $1500, what

is the profit that the store owner makes as a percent and as a dollar amount?

Problem 5

Mr. C owns an organic restaurant and sells vegetable cookies for $2 a bag. If Mr. C spends

$1.50 on a bag of cookies, what is his profit as a percent and as a dollar amount?



Discount Problems

Steps





Answers

1) __________

2) __________

3) __________

4) __________

5) __________

Example

A pair of pants normally sells for $45. The pants are on sale for 20% off. What is the sale

price of the pants?


20% * $45 = X

0.20 * $45 = X

$9 = X Note: $9 is the discount

Sale Price = $45 -- $9 = $36 Sale Price = $36

Practice

Find the percentage.

Problem 1

A car that normally sells for $4500 is on sale for 10% off. What is the sale price of the car?

Problem 2

A TV that normally sells for $1545 is on sale for 40% off. What is the sale price of the TV?

Problem 3

A 1 carrot dianond and gold ring that normally sells for $9000 is on sale for 35% off. What is

the sale price of the ring?

Problem 4

In a grocery store, a $12 case of soda is labeled, "Get a 20% discount." What is the discount?

What is the sale price of the case of soda?

Problem 5

In a grocery store, a $1500 gas grill is labeled, "Buy today and get a 30% discount." What is

the discount? What is the sale price of the grill?



Markup Problems

Steps





Answers

1) __________

2) __________

3) __________

4) __________

5) __________

Example

Susana owns an auto parts store. She uses a 30% markup on all items. If she pays $95 for a

battery, what is the regular price of the battery?


30% * $95 = X

0.30 * $95 = X

$28.5 = X Note: $28.5 is the profit that the owner keeps

Sale Price = $95 + $28.5 = $123.5 Sale Price = $123.5

Practice

Find the percentage.

Problem 1

Alfredo owns a pharmacy. He uses a 25% markup on all items. If she pays $20 for an alergy

medicine, what is the sale price of the alergy medicine?

Problem 2

Alma owns a shoe store. She uses a 25% markup on all shoes. If she pays $120 for a pair of

shoes, what is the selling price of the shoes?

Problem 3

A locar grocery store uses a 40% markup on all meet and dairy products. If the owner pays

$3.00 per pound of cheese, what is the selling price of one pound of cheese?

Problem 4

An airplane manufacturer plans to increase the selling price of their jetliners. With a selling

price of $350 million and a cost of $230 million, what was the percent markup based on

cost?

Problem 5

A jewelry store wants to use a markup of 120% for all items. If a necklace is price at

$2595, how much did the store pay for the necklace?



Simple Interest Problems

Equation

Interest = Principal*Rate *Time Where

Interest = Amount of money that the account will earn over a period of time

Principal = Initial amount of money in the account

Rate = Percent express as a decimal

Time: Years

Steps

1. Write the interest equation.

2. Find the principal

3. Find the interest rate as a decimal

4. Find the time in years

Answers

1) __________

2) __________

3) __________

4) __________

Example 1

Juan invested $3000 in a savings account that pays an annual interest rate of 8% simple

interest. If Juan does not deposit or withdraw any money, how much money would be in his

account after two years?

Interest= Principal*Rate *Time Total amount in account = $3000 + $480

Interest= $3000*8% *2 Total amount in account = $3480

Interest= $3000*0.08 *2

Interest= $480

Solution

Juan will have in his account $3480.

Problem 1

Rosa invested $1500 in a savings account that pays an annual interest rate of 5% simple

interest. If she does not deposit or withdraw any money, how much money would be in her

account after five years?

Problem 2

Ruben invested $500 in a bussines that pays 15% anually. How much money will the

investment earn in 5 years?

Problem 3

Alma deposites $10000 on a savings account that pays 10% annual interest. If she does not

deposites of withdraws any money for a period of 3 years, how much money would she have

on her account?

Problem 4

Jose wants to open a savings account for future investments. He has $10000 and wants to

find out how much money he will have after a period of five years if the bank gives him a

rate of 4%?



Compound Interest Problems

Equation t*n

n

r1PA

Where

A = Balance of the account

P = Principal amount (the initial amount you borrow or deposit)

t = Number of years the money is in the account

r = Annual rate of interest express as a decimal

n = Number of time the interest is compounded per year

Steps

1. Write the compound interest equation.

2. Find the principal

3. Find the interest rate as a decimal

4. Find the time in years

5. Find the amount of times the interest is compounded

Answers

1) __________

2) __________

3) __________

Example 1

$1500 is deposited in a bank account that pays an annual interest rate of 4.3% compounded

quarterly. What is the balance of the account after a period of 6 years?

Given Information

A= X

P= $1500

r= 4.3% = 0.043

n= quarterly = 4 times per year

t = 6 years

t*n

n

r1PA

$1739A

4

0.0431$1500A

*64

Solution

Juan will have in his account $3480.

Problem 1

Mr. C deposit $1200 in a bank account that pays an annual interest rate of 4% compounded

quarterly. What is the balance of the account after a period of 6 years?

Problem 2


monthly. What is the balance of the account after a period of 7 years?

Problem 3


twice a year. What is the balance of the account after a period of 10 years?


Lesson 14: Test Your Knowledge

A pair of pants normally sells for $50. The pants are on sale for 10% off. What is the sale

price of the pants?

The owner of a store uses a 20% markup on all items. If the store purchases an item for $30,

what is the selling price of this item?

Jesus invested $1200 in a savings account that pays an annual interest rate of 3% simple

interest. If Jesus does not deposite or withdraw any money, how much money will be in the

account after one year?

Cesar invested $5000 in a savings account that pays an annual interest rate of 8% twice per

year. If Cesar does not deposite or withdraw any money, how much money will be in the

account after one year?

Olga earns a 13% commission on each item that he sells. What is his commission on a sale of

$490?

Mr. Casillas is invested $14500 in a sabings account that pays an annual interest rate of 8%

compounded twice per year. If Mr. Casillas does not deposite or withdraw any money, how

much money will be in his account after one year?

A refrigerator regularly sells for $1800. It is on sale for 10% off. What is the sale price of the

refrigerator?

Rosa earns a 14% commision on each house that she sells. What is her commision on a house

that sell for $120000?

Richard earn 8% commission on a car sale of $5900. How much money did he make on this

sale?

Ruben invested $1500 in a sabings account that pays an annual interest rate of 10%

compounded once per year. If Ruben does not deposite or withdraw any money, how much

money will be in his account after 3 year?

A television that regularly sells for $2000. It is on sale for 15% off. What is the sale price of

the Television?

Rosio earns a 16% commision on each item that she sells. What is her commision on a house

that sell for $5000?

Answers

1) ________

2) ________

3) ________

4) ________

5) ________

6) ________

7) ________

8) ________

9) ________

10) ________

11) ________

12) ________

lesson 14 solving percent problems

Documents