kris610 wrote:Two cars , L and M, start at the same time and travel side-by-side along a straight road in the same direction until one of the cars is 50 km farther than the other. At the time, how long will have each car traveled?
A) At that time, car L will have traveled 1.5Km for every 1Km traveled by M.
B) At the time, M will traveled at a rate of 50 Km/Hr.
We're looking for how long will each car have traveled- not how far. If it were how far, then A would be sufficient. However, we need to know the speed of each car to determine the time.
a) From this we know that car L is traveling 50% faster than car M. So we know that when car L is 50km ahead of M, L will have traveled 150km and M, 100km. However, we don't know how it will take because we don't know the speed. Insufficient.
b) M travels at 50kph. The missing piece to the equation, but by itself, it's insufficient.
1&2 together: Sufficient. We don't have to do the computation, but if we did, M travels at 50kpm, L then travels at 75kph. They will have traveled for 2 hours to get to distances of 150km and 100km.
