The population of old town is currently 275,000 and it's a cleaning at an annual rate is 1%. The population of new town is 150,000 is increasing at an annual rate of 2%. If the rate of decrease and increase remain constant, after how many years will the population of the two towns be about equal? The answer is 20 I just need help finding how to get 20.

Acookie manufacturer advertised that every bag of a certain type of cookie contained at least 1000 chocolate chips. a consumer group bought 15 bags of cookies from a variety of locations, dissolved the cookies in water and hand-counted the number of chocolate chips in each bag. the average number of chocolate chips was 1161.6 and the standard deviation 117.6. a26. assuming a normal distribution, a 95% confidence interval for the mean number of cookies in each bag is (a) 1108.37 (b) 1108.13 (c) 1102.09 (d) 1096.86 to 1226.34 to 1214.83 to 1215.07 to 1221.11 (e) 1096.47 to 1226.73