Question

The monthly rent of Marilyn's house went from $500 to $440. If p is the percent decrease in the rent, which proportion can be used to calculate p?

A. ($440 - $500) / $440 = p / 100
B. ($440 - $500) / $500 = p / 100
C. $500 / 100 = ($440 - $500) / p
D. $440 / 100 = ($440 - $500) / p

Answer 1

The correct proportion to find the percent decrease in Marilyn's rent is B. ($440 - $500) / $500 = p / 100, which indicates a 12% decrease.

Step-by-step explanation:

To calculate the percent decrease in Marilyn's monthly rent, we must find the amount of the decrease and then divide that by the original amount. This gives us the ratio of the decrease to the original price, which we then convert into a percentage.

The correct proportion to use in this case is: B. ($440 - $500) / $500 = p / 100. This proportion signifies that the decrease in rent ($60) divided by the original rent ($500) equals the percent decrease (p) divided by 100.

The calculation is as follows: ($440 - $500) / $500 = -60 / 500 = -0.12. Since the decrease in rent is a reduction, p will be a positive value and we get p = 12%.