Official Solution:When a positive integer \(x\) is divided by 91, the remainder is 49. What is the remainder when \(2x\) is divided by 13 ? A. 0
B. 7
C. 10
D. 12
E. 49
\(x\) divided by 91, yielding a remainder of 49, can be expressed as \(x = 91q + 49\). Multiplying by 2 gives: \(2x = 2*91q + 98\). This can be rewritten as \(2x = 13*(14q + 7) + 7\). The first term, \(13*(14q + 7)\), is divisible by 13, and the last term, 7, when divided by 13, gives a remainder of 7.
Alternatively, we can reason as follows: Since a PS question can have only one correct answer, then considering one particular case which satisfies the conditions given must also yield the correct answer. If \(x\) divided by 91 yields a remainder of 49, then \(x\) can be 49. In this case, \(2x=98\), and 98 divided by 13 leaves a remainder of 7: \(98 = 13*7 + 7\).
Answer: B