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

[EX Q]: Problem: two trains of length 100 meters and 200 meters are 450 meters apart . they are moving towards each other on parallel tracks , at speeds of 90 km / h and 72 km / h . after how many seconds will the trains meet ?
[EX A]: 10

[EX Q]: Problem: in one alloy there is 12 % chromium while in another alloy it is 8 % . 35 kg of the first alloy was melted together with 40 kg of the second one to form a third alloy . find the percentage of chromium in the new alloy .
[EX A]: 9.75 %

[EX Q]: Problem: a grocer has a sale of rs . 5255 , rs . 5840 , rs . 5921 , rs . 6022 and rs . 6499 for 5 consecutive months . how much sale must he have in the sixth month so that he gets an average sale of rs . 5500 ?
[EX A]:
4463