If x, y, and k are positive numbers such that (x/(x+y))10 + ( y/(x+y) )20 = k and if x < y, which of the following could be the value of k?
10
12
15
18
30
ANS is D, why???
10
12
15
18
30
ANS is D, why???
I did this by plugging the values
So ,
if u solve the equation in the question stem u get
10 ( x+2y) / (x+y) = k
Now just plug the value of each ans choice instead of K
you will see that the only solution where x<y and both are positive is with 18 as the ans.
Is there a better way to do this?
