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

[EX Q]: Problem: a train traveling at 72 kmph crosses a platform in 33 seconds and a man standing on the platform in 18 seconds . what is the length of the platform in meters ?
[EX A]: 300 meters

[EX Q]: Problem: if log 2 = 0.3010 and log 3 = 0.4771 then the value of log 4.5 is :
[EX A]: 0.6532

[EX Q]: Problem: crazy eddie has a key chain factory . eddie managed to decrease the cost of manufacturing his key chains while keeping the same selling price , and thus increased the profit from the sale of each key chain from 20 % of the selling price to 50 % of the selling price . if the manufacturing cost is now $ 50 , what was it before the decrease ?
[EX A]:
$ 80