dpark wrote:
If t is a positive integer and r is the remainder when t^2+5t+6 is divided by 7, what is the value of r?
(1) When t is divided by 7, the remainder is 6.
(2) When t^2 is divided by 7, the remainder is 1.
Statement (1) Says that when t is divided by 7, the reminder is 6.
Say : t = 7A + 6
t^2 = 47A^2 + 84A + 36
Hence, when t^2 is divided by 7, the remainder is 1.
5t = 35A + 30
Hence, when 5t is divided by 7, the remainder is 2.
Hence, the remainder of t^2+5t+6 is divided by 7 would be (1+2+6)/7 = 2
So, statement 1 is sufficient.
From statement 2, we cant derive what would be the value of t as t^2 can be 1 , 36, 64 ... so on. Hence, not sufficient.