instruction:
The task is to generate the correct answer for a given math problem.
question:
Problem: robert ' s salary was decreased by 20 % and subsequently increased by 20 % . how much percentage does he lose ?
answer:
4 %


question:
Problem: in a new housing development , trees are to be planted along the sidewalk of a certain street . each tree takes up one square foot of sidewalk space , and there are to be 9 feet between each tree . how many trees can be planted if the road is 151 feet long ?
answer:
1


question:
Problem: the present population of a town is 1240 . population increase rate is 4 % p . a . find the population of town after 1 years ?
answer:

129