Question

Suppose the equation E = $500 + $7x represents a person's earnings (+) for

each item (x) sold. Assuming that only a whole number of items can be sold, which of the following values of E is possible?

A. $430
B. $530
C. $680
D. $780

Answer 1

Option D : $780 is the correct answer.

Explanation:

Given expression is:

E = $500 + $7x

We will put all the values of given options to check.

A. Putting 430 in given expression

430 = 500 + 7x

430 - 500 = 7x

-70 = 7x

As the number of items sold cannot be negative, therefore, this option is not correct.

B. 530 = 500 + 7x

530 - 500 = 7x

30 = 7x

x = 4.3 (By dividing both sides by 7)

Which is not a whole number.

C. 680 = 500 + 7x

680 - 500 = 7x

7x = 180

x = 25.71

Which is also not a whole number.

D. 780 = 500 + 7x

780 - 500 = 7x

280 = 7x

7x = 280

x = 40

Which is a whole number.

Hence,

Option D : $780 is the correct answer.