Which of the following is a biotic factor A)light intensity
B) food supply
C) pollution
D) temperature ​

B) food supply.

Explanation:

The answer is B

Part a) The new price is

Part b) The percent decrease is 20%

Part c) The percent decrease is 9.375%

Step-by-step explanation:

we know that

The original price of a sofa is $500

This price represent the 100%

Part a) If the sofa price decreased by 20%, what is the new price?

Let

x -----> the new price

we know that

so

The new price is equal to the original price multiplied by 0.80

Part b) The company can’t sell the sofa after 3 weeks so they reduce the price to $320. What is the percent decrease?

In this moment the price of sofa is $400

Find the difference between the original price and the new price

using proportion

Find out the percent decrease

Let

x ----> the percent decrease

Part c) If the company reduces the price in week 4 to $290, what is the percent decrease?

In this moment the price of sofa is $320

Find the difference between the original price and the new price

using proportion

Find out the percent decrease

Let

x ----> the percent decrease