Acity population, which was initially 15,500, has been dropping by 3% a year. the graph below represents this function. we'll use this information to find out how long it will take for the population to be less than 8000 people. can some one me solve this

8000=15500(1-0.03)^x
Solve for x
X=22years

A) So if your friend started walking 3 miles per hour for 5 minutes the first step to take is to divide 5 by 60 because she walked 5 out of 60 minutes for 3 mph. You then get the fraction 1/12. Next you want to multiply 3 mph by 1/12 to get the answer 1/4 miles. So the answer for A is the girl walked a quarter (0.25 miles) in the 5 minute headstart. 

B) Based off the previous answer she should be 0.25 miles ahead of you by the time you start walking. For this problem you would need a graph, the equations for the graph I got were y=3x+0.25 and y=4x+0. Simply graph after this and find the intercept, to determine the amount of time it took you need to view where the two lines intercept, and the x value is the amount of time it took. The x value I got was 0.25. So 60*0.25 is 15, it took you 15 minutes to catch up with her at 1 miles from the start point.