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by Rich.C@EMPOWERgmat.com » Fri Mar 16, 2018 10:42 am
Hi LUANDATO,

DavidG brings up a good point - when TESTing VALUES in these types of questions, the easiest value for X is almost always the remainder itself. That having been said, you don't have to use that value to get the correct answer. If we use X = 28, then 28/20 = 1 r 8.... and the answer to the question is 28/5 = 5 r 3 --> so the answer is still 3.

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by Scott@TargetTestPrep » Mon Mar 19, 2018 3:31 pm
LUANDATO wrote:When positive integer x is divided by 20, the remainder is 8. What is the remainder when x is divided by 5?

A. 1
B. 3
C. 5
D. 8
E. Cannot be determined
We can create the equation:

x/20 = Q + 8/20

x = 20Q + 8

When 20Q + 8 is divided by 5 we have:

(20Q + 8)/5 = 4Q + 8/5

Since 8/5 = 1 3/5, the remainder is 3.

Alternate Solution:

Since we have a remainder of 8 when x is divided by 20, x could equal 28. When we divide 28 by 5, the quotient is 5 with a remainder of 3.

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by deloitte247 » Thu Mar 29, 2018 1:54 pm
$$\frac{x}{20}=Q+\frac{8}{20}$$
$$x=20Q+8$$
$$when\ x\ is\ divided\ by\ 5\ i.e\ \frac{x}{5}=???$$
$$substituting\ 20Q+8=x$$
$$we\ have,\ \frac{\left(20Q+8\right)}{5}=4Q+\frac{8}{5}$$
$$=4Q+1\frac{3}{5}$$
$$Hence,\ the\ remainder\ is\ 3.\ Option\ B$$

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