When two ants work together they can build an anthill in 24
minutes. When the bigger ant works alone, an anthill can be built in 14
minutes less than when the smaller ant works alone. How many minutes
does it take the smaller ant to build an anthill when working
alone?
, 2025
Solution
Let be the number of
minutes that it would take the bigger ant to build an anthill alone and
let be the number of minutes that
it would take the smaller ant to build an anthill alone.
Since the bigger ant can build an anthill in minutes, the bigger ant builds anthills per minute.
Likewise, the smaller ant can build anthills per minute.
Thus, working together, the two ants build anthills per
minute.
It is also given that it takes the two ants minutes to build an anthill together,
so this means they build anthills per minute working
together.
Hence, we get the equation .
Multiplying this equation through by gives .
From the other given condition, we get , so we can substitute to get .
Expanding and rearranging, this equation becomes , which can be factored as
.
If , then , which does not make sense since
must be positive. Therefore,
.