Worksheet with percentage increase and decrease word problems for math practice.

Let's solve each problem step by step.

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Problem 1:

Last week I bought a kilogram of tomatoes for $2. This week the price was only $1.50 a kilogram. By what percentage did the price decrease?

#### Solution:
1. Identify the original and new prices:
- Original price = $2
- New price = $1.50

2. Calculate the decrease in price:
\[
\text{Decrease} = \text{Original Price} - \text{New Price} = 2 - 1.50 = 0.50
\]

3. Calculate the percentage decrease:
\[
\text{Percentage Decrease} = \left( \frac{\text{Decrease}}{\text{Original Price}} \right) \times 100 = \left( \frac{0.50}{2} \right) \times 100 = 0.25 \times 100 = 25\%
\]

#### Answer:
\[
\boxed{25\%}
\]

---

Problem 2:

Yesterday at noon the temperature was 32 degrees Celsius. Today at noon it was 40 degrees. By what percentage did the temperature increase?

#### Solution:
1. Identify the original and new temperatures:
- Original temperature = 32°C
- New temperature = 40°C

2. Calculate the increase in temperature:
\[
\text{Increase} = \text{New Temperature} - \text{Original Temperature} = 40 - 32 = 8
\]

3. Calculate the percentage increase:
\[
\text{Percentage Increase} = \left( \frac{\text{Increase}}{\text{Original Temperature}} \right) \times 100 = \left( \frac{8}{32} \right) \times 100 = 0.25 \times 100 = 25\%
\]

#### Answer:
\[
\boxed{25\%}
\]

---

Problem 3:

The price of a liter of milk increased 10% compared with last year. If the new price is $1.21 per liter, what was last year’s price?

#### Solution:
1. Let the last year’s price be \( x \).
- The new price is 10% more than last year’s price, so:
\[
\text{New Price} = x + 0.10x = 1.10x
\]

2. We know the new price is $1.21:
\[
1.10x = 1.21
\]

3. Solve for \( x \):
\[
x = \frac{1.21}{1.10} = 1.10
\]

#### Answer:
\[
\boxed{1.10}
\]

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Problem 4:

Maria works and gets $7.50 per hour. Her boss is so happy with her work that he decided to raise her pay with $1.50 per hour. What percentage was her pay raise?

#### Solution:
1. Identify the original pay and the raise amount:
- Original pay = $7.50
- Raise amount = $1.50

2. Calculate the percentage raise:
\[
\text{Percentage Raise} = \left( \frac{\text{Raise Amount}}{\text{Original Pay}} \right) \times 100 = \left( \frac{1.50}{7.50} \right) \times 100 = 0.20 \times 100 = 20\%
\]

#### Answer:
\[
\boxed{20\%}
\]

---

Problem 5:

Peter deposited 1,000 dollars in a bank account. After 5 years he had $1,500 in his account. By what percentage did his bank balance grow?

#### Solution:
1. Identify the original and final amounts:
- Original amount = $1,000
- Final amount = $1,500

2. Calculate the increase in the bank balance:
\[
\text{Increase} = \text{Final Amount} - \text{Original Amount} = 1,500 - 1,000 = 500
\]

3. Calculate the percentage increase:
\[
\text{Percentage Increase} = \left( \frac{\text{Increase}}{\text{Original Amount}} \right) \times 100 = \left( \frac{500}{1,000} \right) \times 100 = 0.50 \times 100 = 50\%
\]

#### Answer:
\[
\boxed{50\%}
\]

---

Problem 6:

The rent on my apartment is $1,200 a month. I asked the landlord to lower the rent by 10%. Luckily he agreed. What is the new monthly rent I have to pay?

#### Solution:
1. Identify the original rent and the percentage decrease:
- Original rent = $1,200
- Decrease percentage = 10%

2. Calculate the decrease in rent:
\[
\text{Decrease} = \text{Original Rent} \times \text{Decrease Percentage} = 1,200 \times 0.10 = 120
\]

3. Calculate the new rent:
\[
\text{New Rent} = \text{Original Rent} - \text{Decrease} = 1,200 - 120 = 1,080
\]

#### Answer:
\[
\boxed{1080}
\]

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Final Answers:

1. \(\boxed{25\%}\)
2. \(\boxed{25\%}\)
3. \(\boxed{1.10}\)
4. \(\boxed{20\%}\)
5. \(\boxed{50\%}\)
6. \(\boxed{1080}\)