Question

The average price of gas increased by 10 percent during one year. If x represents the average price of gas at the beginning of the year and y represents the average price of gas at the end of the year, which of the following is true?

A. x = 0.1y
B. y = 0.1x
C. y = x + 0.1
D. y = 1.1x
E. x = 1.1y

Answer 1

The correct expression for the average price of gas at the end of the year, after a 10% increase from the beginning of the year, is y = 1.1x.

Step-by-step explanation:

If the average price of gas increased by 10 percent during one year, and we let x represent the average price of gas at the beginning of the year and y represent the average price of gas at the end of the year, then we can calculate the end of the year price as the beginning of the year price plus 10% of the beginning price. This can be expressed as y = x + 0.1x, which simplifies to y = 1.1x.

This percentage increase implies that the new price is 110% of the original price, hence the multiplication by 1.1. Answer: D. y = 1.1x is the correct expression describing the relationship between the average price of gas at the beginning (x) and at the end of the year (y).