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

Ex Input:
Problem: 10 women can complete a work in 5 days and 10 children take 10 days to complete the work . how many days will 5 women and 10 children take to complete the work ?

Ex Output:
5


Ex Input:
Problem: two pipes can fill the cistern in 10 hr and 12 hr respectively , while the third empty it in 30 hr . if all pipes are opened simultaneously , then the cistern will be filled in

Ex Output:
6.67 hr


Ex Input:
Problem: a distributor sells a product through an on - line store , which take a commission of 20 % of the price set by the distributor . the distributor obtains the product from a producer at the price of $ 15 per item . what is the price that the buyer observers on - line if the distributor wants to maintain a 30 % profit on the cost of the item ?

Ex Output:

25.7