Mathematics

Mathematics

Problem

A nest of ants initially contains 500 individuals. The population is increasing by 12% each week. a. How many ants will there be after:    i 10 weeks    ii 20 weeks? b. How many weeks will it take for the ant population to reach 2000?
Intuitive explanation

The key here is exponential growth: when a quantity increases by a fixed percentage each time period, it multiplies by the same factor repeatedly. Rather than adding 12% of the original 500 each week (which would be linear), you're adding 12% of whatever you have, so the population compounds. To model this, use the form P(t)=P0(1+r)tP(t) = P_0(1 + r)^t, where rr is the growth rate as a decimal and tt is the number of weeks—this captures how each week's growth builds on the last.

Intuitive explanation

The key here is exponential growth: when a quantity increases by a fixed percentage each time period, it multiplies by the same factor repeatedly. Rather than adding 12% of the original 500 each week (which would be linear), you're adding 12% of whatever you have, so the population compounds. To model this, use the form P(t)=P0(1+r)tP(t) = P_0(1 + r)^t, where rr is the growth rate as a decimal and tt is the number of weeks—this captures how each week's growth builds on the last.

Browse the problem library