Traveling downstream from P to Q and upstream from Q to P takes a boat three hours in total. In calm water, what is the boat's speed?I. The river current travels at a pace of one kilometre per hour., II. P and Q are 4 kilometres apart.
A. I alone sufficient while II alone not sufficient to answer
B. II alone sufficient while I alone not sufficient to answer
C. Either I or II alone sufficient to answer
D. Both I and II are necessary to answer
Answer:D
Traveling downstream from P to Q and upstream from Q to P takes a boat three hours in total. In calm water, what is the boat's speed?I. The river current travels at a pace of one kilometre per hour., II. P and Q are 4 kilometres apart.
A. I alone sufficient while II alone not sufficient to answer B. II alone sufficient while I alone not sufficient to answer C. Either I or II alone sufficient to answer D. Both I and II are necessary to answer
Explanation: The present speed is 1 km/hr.PQ = 4 km, II.Let's say the boat's speed in calm water is x km/hr. Then,3 = 4/(x + 1) + 4/(x - 1) This results in x.