Question

A population of rodents increases exponentially at a rate of 7.5% per year.

What is the equivalent monthly rate to the nearest hundredth of a percent?

0.03%

0.60%

0.62%

0.81%


A population of butterflies decreases exponentially at a rate of 18.3% per year.

What is the equivalent monthly rate to the nearest hundredth of a percent?


1.27%

1.41%

1.53%

1.67%

Answer 1

1. the answer is "0.62%".
We can calculate this as;
Rate = 7.5% per year
there are 12 months in a year so,
= 7.5/ 100 x 1/12
=0.075 x 1/12
= 0.00625
for percentage multiply it with 100,
= 0.00625 x 100
=0.625% = 0.62%
2.the answer is "1.53%".
We can calculate this as;
Rate = 18.3% per year
there are 12 months in a year so,
= 18.3/ 100 x 1/12
=0.183 x 1/12
= 0.01525
for percentage multiply it with 100,
= 0.01525 x 100
=1.525% = 1.53%