Q: Whats the values of x and yjayanti wrote:What is the value of xy?
(1) 2^(x+y) = 4
(2) 2^(x+3y) = 16
(1)
2^(x+y) = 4
2^(x+y) = 2^2
x+y = 2
x=2-y
y=2-x
Can't get the values of x and y. Hence Insuff.
(2)
2^(x+3y) = 16
2^(x+3y) = 2^4
x + 3y = 4
x=4-3y
y=(4-x)/3
Can't get the values of x and y. Hence Insuff.
Together:
From (1) we know, x=2-y and from (2) we know x=4-3y
4-3y=2-y
-2y=-2
y=1
from (1) x=2-y
x=2-1
x=1
Hence x.y = 1
Therefore suff.
(C)
