Question

If x, y, and k are positive numbers such that ((10x)/(x+y)) + ((20y)/(x+y)) = k and if x < y, which of the following could be the value of k?
A. 10
B. 12
C. 15
D. 18
E. 30

Answer 1

nops..30 is not the ans..

Answer 2

what makes you go for 30?

Answer 3

give me a sec

Answer 4

12 or 18

Answer 5

is dat rite??

Answer 6

18's the ans..
but i'd to know your solns..
i'll post mine after some time..

Answer 7

in the LHS the second term is positive....so the ans is GREATER than 10
and ti get 15....(y/x+y)=1/2....which means x=y which is not possible

and obviously 30 is ruled out...