Bunuel wrote:

A marathon runner running along a prescribed route passes through neighborhoods J, K, L, and M, not necessarily in that order. How long does it take to run from J to M?

(1) The runner averages 8 miles per hour on the route from J to M.

(2) M is 4 miles from K and 12 miles from L, but J is 15 miles from K.

We need to know the time it takes the runner from J to M.

Statement 1Gives us the speed from J to M, but without distance we cannot calculate the time. So

not sufficient.

Statement 2from the statement it is clear that even if we do some work on this, we might get the distance, but nothing given about speed. So no way can we determine the time. So

not sufficient.

Combining the two statements, now we need to work on distance from statement 2.

L......(12)......M..(4)..K........(15).......J

Above is one order possible, here distance between J and M = 15+4 = 19

L......(8)..K..(4)..M......(11).....J

Above order is also possible, please note that here also distance between M and K is 4 miles, that between M and L is 12 miles, that between J and K is 15 miles. So the distance between J and M here = 11.

Since we are getting multiple answers for distance between J and M, we will have multiple answers for the time taken too. A unique answer for the time taken thus cannot be determined.

Not sufficient still.

Hence

E answer