If x is a positive integer, is the remainder 0 when 3^x + 1 is divided by 10?
(1) x = 4n + 2, where n is a positive integer.
(2) x > 4
(1) x = 4n + 2, where n is a positive integer.
(2) x > 4
Statement 1: x = (4n + 2), where n is positive.jayanti wrote:If x is a positive integer, is the remainder 0 when 3^x + 1 is divided by 10?
(1) x = 4n + 2, where n is a positive integer.
(2) x > 4
As x is 2 more than a positive multiple of 4, the unit's digit of 3^x will be 9. Hence, the unit's digit of (3^x + 1) will be 0.
Therefore, when (3^x + 1) will be divided by 10, the remainder will be equal to 0.
Sufficient
Statement 2: Not enough information to conclude anything.
Not sufficient
The correct answer is A.
