The task is to generate the correct answer for a given math problem.

[EX Q]: Problem: if the radius of a circle is decreased 60 % , what happens to the area ?
[EX A]: 84 % decrease

[EX Q]: Problem: a train crosses a bridge of length 200 m in 10 seconds and a lamp post on the bridge in 5 seconds . what is the length of the train in metres ?
[EX A]: 200 m

[EX Q]: Problem: excluding stoppages , the speed of the bus is 54 kmph and including stoppages , it is 36 kmph . for how many minutes does the bus stop per hr
[EX A]:
20 mi