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

[EX Q]: Problem: a retailer buys 80 pens at the market price of 36 pens from a wholesaler , if he sells these pens giving a discount of 1 % , what is the profit % ?
[EX A]: 12

[EX Q]: Problem: a tyre has two punctures . the first puncture alone would have made the tyre flat in 9 minutes and the second alone would have done it in 6 minutes . if air leaks out at a constant rate , how long does it take both the punctures together to make it flat ?
[EX A]: 335 min

[EX Q]: Problem: arjun started a business with rs . 20,000 and is joined afterwards by anoop with rs . 30 , 000 . after how many months did anoop join if the profits at the end of the year are divided equally ?
[EX A]:
4