The answer would be x equals 7
1. can't be determined cause no info given on the rate of which the population is growing.
2. can't be determined/not true because the initial population of a could be less than b.
3. can't be determined/not true because we don't have enough info to tell how fast they grow and decline.
II hope this helps it’s pretty simple
1.750
3.516540
4.354.2
5.3560
6.4.73
7.1277.2
8.4544
9.813000
10.0.02532
11.3160000
12.0.00335
13.26310
14. 918.7
15. 9320
16.8.42
17.45160000
18.0.005435
19.2450
20.656.9
Hope this helps!
Markup means they sell it for that percentage more than they bought it for. First let's calculate how much they will mark it up for:

Convert 87% into a decimal(87/100):

Multiply:

This is how much they'll mark it up, now let's add it to how much they bought it for to find out the selling price: