The population of boomtown

Question

The population of Boomtown is currently 7000 and expected to grow by 3.2% over the next year. What will its population be by then?



The population of Dullsville, on the other hand, is currently 2000 and expected to decrease by 3.6% over the next year. What will its population be by then?

Answer 1

Hi Christopher,

 

A growth of 3.2% in an increase of 3.2%. There are 2 ways of solving this

1) Two step approach: calculate 3.2% of 7000 and add that number back to 7000...224 + 7000 = 7224

2) One step approach: calculate 103.2% of 7000 = 7224

----This works because 100% (the original amount) + 3.2% (the growth) = 103.2%

 

A decrease of 3.2% is the opposite of a growth. There are 2 ways of solving this
1) Two step approach: calculate 3.6% of 2000 and subtract that number from 2000...2000 - 72 = 1928
2) One step approach: calculate 96.4% of 2000 = 1928

----This works because 100% (the original amount) - 3.6% (the growth) = 96.4%

Answer 2

7000 x .032 will give you the growth, so add that to 7000 to get the new population.