If r, s, and t are all positive integers, what is the remainder of 2^p/10, if p = rst?
(1) s is even
(2) p = 4t
(1) s is even
(2) p = 4t
i would got for B for thisddm wrote:If r, s, and t are all positive integers, what is the remainder of 2^p/10, if p = rst?
(1) s is even
(2) p = 4t
P= rst
statement 1. s is even .
thus from this we know rst will so will be even
but then
assume rst =4
2^4 /10 = 6 as remainder
2^6 /10 = 4 as remainder
hence insufficient
Statement B
p =4t
thus we know P is a factor of 4
2^ any factor of 4 divided by 10 will always leave a remainder of 6.
hence B is sufficient.
thus B.
hope that helps..
