Bunuel
What is the remainder when the positive integer n is divided by 2?
(1) When n is divided by 13, the remainder is 3
(2) n + 2 is a multiple of 7
(1) When n is divided by 13, the remainder is 3
n is of the form:
\(n=13q+3\)-----> if we divide 13q+3 by 2, we will get multiple values for remainders.
if \(q=;1 n=13+3=16\) in that case remainder will be 0.
if \(q=2;n=26+3=29\) in this case remainder will be 1.
clearly Not sufficient.
(2) n + 2 is a multiple of 7.
this means, \(7q=n+2\), where q is any integer: 1,2,3,4...
\(n=7q-2\)
\(7q-2 / 2\) gives multiple remainders as well.
if q=1; \( n=7*2-2= 12\). in this case, when divided by 2, remainder will be 0
if q=3; \(n=7*3-2=19\).in this case, when divided by 2, remainder will be 1
Not sufficient.
1+2 together.
\(n=13q+3\) and n+2 is a multiple of 7
therefore, \(n+2= 13q+3+2\)----> \(n+2=13q+5\) is also a multiple of 7. again, q can be any integer=1,2,3,4...
you don't need to "solve" further it's clear we're kinda in a circle now. since q can be any integer this will not give one single result.
Hence, E.