If x = 3^21 and y = 6^55, what is the remainder when 2x + y is divided

Question

If x = 3^21 and y = 6^55, what is the remainder when 2x + y is divided by 5?

(A) 0
(B) 1
(C) 2
(D) 3
(E) 4

CrackverbalGMAT · Answer

2x + y = 2 * 3^{21} + 6^{55}

When dividied by 5, the expression becomes  \frac{2 * 3^{21} + 6^{55}}{5}

Since neither of the terms in the numerator are divisible by 5, we can separately divide each term.

For the first term 3^4 = 81 , which gives a remainder of 1 when divided by 5

For the second term, 6 gives a remainder of 1 when divided by 5, therefore  6^{55} , when divided by 5 gives a remainder of 1.

R  + R  = R  + 1 = 1 + 1 = 2

Option C

Arun Kumar

kntombat · Answer

Bunuel , could you provide the OE for this question please, I got the answer as C.

Bunuel · Answer

C is correct. Edited the OA. Thank you!

Prep Toolkit