Answer:
There were 12 donuts in the box.
Explanation:
We are given the following information in the question:
Let x be the number of donuts in the box.
Then, according to the question
Number of donuts eaten by Amy =
![(2x)/(3)](https://img.qammunity.org/2020/formulas/mathematics/middle-school/40i4cm7wvkr5u4307gbt2z6cpkt7mx2o.png)
Number of donuts eaten by Anna =
![(x)/(4)](https://img.qammunity.org/2020/formulas/mathematics/middle-school/s9pl5chb7mhiw74d0q6m9r578webn125wl.png)
Number of donuts eaten by David = 1
Total number of donuts =
Number of donuts eaten by Amy + Number of donuts eaten by Anna + Number of donuts eaten by David
![\Rightarrow (2x)/(3) + (x)/(4) + 1 = x](https://img.qammunity.org/2020/formulas/mathematics/middle-school/wfb6m0g2dkcuw2rf4xiffw1lwak5fpi5q0.png)
Solving the above equation:
![11x + 12 = 12x\\x =12](https://img.qammunity.org/2020/formulas/mathematics/middle-school/ln4ygtr037aih89tbrduoou7mt4m9lrava.png)
Thus, there were 12 donuts in the box.