"Percent decrease" refers to the percentage change in the value when it decreases over a certain period of time. For example, a decrease in rainfall and a decrease of temperature in winter are a few examples of percent decrease.
The percentage decrease value is calculated by the percentage decrease formula, and the value is given in percent.
Percent Decrease =
\frac{old value - new value}{old value} × 100
The percentage decrease formula is the method of calculating the decrease in percentage from its initial value. It refers to the decrease in the value of something with reference to its initial one.
The percentage decrease formula can be derived in two simple steps.
Step 1: Determine the difference between the values.
Percentage decrease = old value - new value
Step 2: Divide the obtained value by the old value and multiply it by 100. To obtain the value in percentage.
Percentage decrease =
\frac{old value - new value}{old value} × 100
Hence, the percentage decrease formula is the decreased percent value obtained by dividing the difference of values by the old value and multiplying it by 100.
Also Check
Sample Problems
Question 1: What is the percentage decrease from 12000 to 11600?
Solution:
Given:
The old value is 12000.
The new value is 11600
⇒ Percentage decrease = (12000 - 11600/12000) × 100
⇒ Percentage decrease = 3.33%
Hence, the percentage decrease is 3.33%.
Question 2: What is the percentage decrease from 120 to 96?
Solution:
Given:
The old value is 120.
The new value is 96
Percentage decrease =
\frac{old value - new value}{old value} × 100⇒ Percentage decrease = (120 - 96/120) × 100
⇒ Percentage decrease = 20%
Hence, the percentage decrease is 20%.
Question 3: What is the percentage decrease from 50 to 10?
Solution:
Given:
The old value is 50.
The new value is 10
Percentage decrease =
\frac{old value - new value}{old value} × 100⇒ Percentage decrease = (50 - 10/50) × 100
⇒ Percentage decrease = 80%
Hence, the percentage decrease is 80%.
Question 4: What is the percentage decrease from 20 to 18?
Solution:
Given:
The old value is 20.
The new value is 18
Percentage decrease =
\frac{old value - new value}{old value} × 100⇒ Percentage decrease = (20 - 18/20) × 100
⇒ Percentage decrease = 10%
Hence, the percentage decrease is 10%.
Question 5: What is the percentage decrease from 100 to 50?
Solution:
Given:
The old value is 100.
The new value is 50
We have,
Percentage decrease =
\frac{old value - new value}{old value} × 100⇒ Percentage decrease = (100 - 50/100) × 100
⇒ Percentage decrease = 50%
Hence, the percentage decrease is 50%.
Question 6: What is the percentage decrease from 2000 to 1600?
Solution:
Given:
The old value is 2000.
The new value is 1600
Percentage decrease =
\frac{old value - new value}{old value} × 100⇒ Percentage decrease = (2000 -1600/2000) × 100
⇒ Percentage decrease = 20%
Hence, the percentage decrease is 20%.
Question 7: What is the percentage decrease from 100 to 160?
Solution:
Given:
The old value is 100.
The new value is 160
Percentage decrease =
\frac{old value - new value}{old value} × 100⇒ Percentage decrease =(160 - 100/100) × 100
⇒ Percentage decrease =60%
Hence, the percentage decrease is 60%.
Question 8: What is the percentage decrease from 600 to 400?
Solution:
Given:
The old value is 600.
The new value is 400.
Percentage decrease =
\frac{old value - new value}{old value} × 100⇒ (Percentage decrease = 600 - 400/400) × 100
⇒ Percentage decrease = 50%
Hence, the percentage decrease is 50%.
Practice Problem Based on Percent Decrease Formula
Question 1: A car was originally priced at $25,000. After a year, the price dropped to $22,000. What is the percentage decrease in the price of the car?
Question 3: The temperature on a winter day was 15°C in the morning and dropped to 10°C by the evening. What is the percentage decrease in temperature?
Question 4: A student scored 90 out of 100 in the first exam. In the second exam, they scored 80 out of 100. What is the percentage decrease in the student's score between the two exams?
Question 5: A student scored 465 out of 500 last year. This year, their score decreased by 5%. What is the student's score this year?
Answer:
- 12%
- 33.33%
- 11.11%
- 442