Task: Question Answering
Input (English): Problem: village x has a population of 72000, which is decreasing at the rate of 1200 per year. village y has a population of 42000, which is increasing at the rate of 800 per year. in how many years will the population of the two villages be equal ?
Options: a. 15, b. 19, c. 11, d. 18, e. 13
Output (English): a