In this task, you need to answer the given multiple-choice question on the general math. Classify your answers into 'a', 'b', 'c', 'd', and 'e'.
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Question: Problem: village x has a population of 76000 , 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 ) 17 , c ) 11 , d ) 18 , e ) 13

Answer: b


Question: Problem: if 7 a - 3 b = 10 b + 50 = - 12 b - 2 a , what is the value of 9 a + 9 b ? 
Options: a ) - 9 , b ) - 6 , c ) 0 , d ) 6 , e ) 9

Answer: c


Question: Problem: the price of a certain painting increased by 10 % during the first year and decreased by 15 % during the second year . the price of the painting at the end of the 2 - year period was what percent of the original price ? 
Options: a ) 102 % , b ) 105 % , c ) 95 % , d ) 93.5 % , e ) 90 %

Answer:
d