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

Ex Input:
Problem: a bullet train covers a distance in 50 min , if it runs at a speed of 48 kmph on an average . the speed at which the bullet train must run to reduce the time of journey to 40 min will be .

Ex Output:
60 kmph


Ex Input:
Problem: country c imposes a two - tiered tax on imported cars : the first tier imposes a tax of 12 % of the car ' s price up to a certain price level . if the car ' s price is higher than the first tier ' s level , the tax on the portion of the price that exceeds this value is 8 % . if ron imported a $ 14,000 imported car and ended up paying $ 1640 in taxes , what is the first tier ' s price level ?

Ex Output:
$ 1300


Ex Input:
Problem: the denominator of a fraction is 7 greater than the numerator . if the numerator and the denominator are increased by 4 , the resulting fraction is equal to 5 â  „ 6 . what is the value of the original fraction ?

Ex Output:

31 / 38