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

Answer: 60 kmph

Question: Problem: two trains , a and b , started simultaneously from opposite ends of a 125 - mile route and traveled toward each other on parallel tracks . train a , traveling at a constant rate , completed the 125 - mile trip in 12 hours ; train b , traveling at a constant rate , completed the 125 - mile trip in 8 hours . how many miles had train a traveled when it met train b ?

Answer: 5

Question: Problem: after decreasing 24 % in the price of an article costs rs . 684 . find the actual cost of an article ?

Answer:
900