mgmat ds 9

[pradeepkaushal9518]

Bob and Wendy planned to walk from their home to a restaurant for dinner together. However, Bob was delayed at work, and Wendy left for the restaurant before Bob did. If the restaurant is 3 miles from their home and Bob left for the restaurant a half-hour after Wendy did, how long did Wendy have to wait for Bob at the restaurant?

(1) Wendy walked at a constant pace of 4 miles per hour

(2) Bob walked at a constant pace of 1 mile per hour faster than Wendy.

[anantbhatia]

C?

[pradeepkaushal9518]

can u explain?

[anantbhatia]

By knowing speed of Wendy we only know how long it'll take her to reach the restaurant. There's no information about speed\time of Bob. Hence A & D ruled out.

For 2,
speed of wendy =w
Speed of Bob= w+1

Time Wendy had to wait= half an hour(constant) + time taken by Wendy - time taken by Bob
= const + 3/w - 3/(w+1). Insufficient to get a value.

We would have known the exact time if we had known the value of w. Hence combining, (C) gives us a result.