If x is divided by 7, the remainder is 5. What is the

VJesus12 wrote:If x is divided by 7, the remainder is 5. What is the remainder if 4x is divided by 7?

A. 1
B. 2
C. 4
D. 6
E. 8

Since when x is divided by 7, the remainder is 5, we can create the following equations in which the quotient = Q:

x/7 = Q + 5/7

x = 7Q + 5

Since we need to determine the remainder when 4x is divided by 7, we can multiply both sides of the equation x = 7Q + 5 by 4 and we have:

4x = 28Q + 20

Finally, we can divide 28Q + 20 by 7:

(28Q + 20)/7

28Q/7 + 20/7

Since 7 divides into 28Q, we are only concerned with the remainder of the division of 20 by 7, which is 6.

Alternate solution:

We are given that when x is divided by 7, the remainder is 5. We can see that a possible number for x is 12. Therefore, we need to determine the remainder when 4x, or in this case, 48, is divided by 7. Since 48/7 = 6, R 6, the remainder is 6.

Answer: D