Village X has a population of 78000, 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

Rationale: "let the population of two villages be equal after p years then , 78000 - 1200 p = 42000 + 800 p 2000 p = 36000 p = 18 answer is d ."
Answer: D