Lesson 12
Finding the Percentage
Let’s find unknown percentages.
Problem 1
A music store marks up the instruments it sells by 30%.
- If the store bought a guitar for $45, what will be its store price?
- If the price tag on a trumpet says $104, how much did the store pay for it?
- If the store paid $75 for a clarinet and sold it for $100, did the store mark up the price by 30%?
Problem 2
A family eats at a restaurant. The bill is $42. The family leaves a tip and spends $49.77.
- How much was the tip in dollars?
- How much was the tip as a percentage of the bill?
Problem 3
The price of gold is often reported per ounce. At the end of 2005, this price was $513. At the end of 2015, it was $1060. By what percentage did the price per ounce of gold increase?
Problem 4
A phone keeps track of the number of steps taken and the distance traveled. Based on the information in the table, is there a proportional relationship between the two quantities? Explain your reasoning.
| number of steps | distance in kilometers |
|---|---|
| 950 | 1 |
| 2,852 | 3 |
| 4,845 | 5.1 |
Problem 5
Noah picked 3 kg of cherries. Mai picked half as many cherries as Noah. How many total kg of cherries did Mai and Noah pick?
\(3 + \frac12\)
\(3 - \frac12\)
\(\left(1+\frac12\right)\boldcdot 3\)
\(1+\frac12\boldcdot 3\)