B starts 4.5 minutes after A from the same point, for a place at a distance of 3.5 miles from the starting point. A on reaching the destination turns back and walk a mile where he meets B. If A's speed is a mile in 6 minutes then B's speed is a mile in ____ minutes?
Show answer & explanation
Correct answer: D
Explanation
The correct answer is option 4 i.e. 9
Distance covered by A = 3.5 mile + 1 mile = 4.5 mile
Distance covered by B = 3.5 mile - 1 mile = 2.5 mile
Speed of A = 1 mile/6 min
1 mile -> 6 min
4.5 mile -> 6 × 4.5 = 27 min
Time taken by B to reach point P = (27 - 4.5) = 22.5 min
Speed of B = 2.5 mile/ 22.5 min = 1 mile/9 min
B's speed is 1 mile in 9 minutes