The depth was 64 feet. Currently, the depth is 80 feet. The depth increased by 25%
Solution:
Given, The depth was 64 feet.
Currently, the depth is 80 feet.
We have to find by what percent has the depth increased
The percentage increase is given as:
![\text { percent increase }=\frac{\text { change in the depth }}{\text { original depth }} * 100 \%](https://img.qammunity.org/2020/formulas/mathematics/middle-school/qkfhqn95rfn23r2uw13rokfhmp7uhnyz2x.png)
Here original depth = 64
Final depth = 80
Change in depth = final depth - original depth = 80 - 64 = 16
Plugging in values in formula we get,
![\begin{array}{l}{\text { Percent increase in depth }=(80-64)/(64) * 100 \%} \\\\ {=(16)/(64) * 100 \%} \\\\ {=(1)/(4) * 100 \%=25 \%} \\\\ {\text { Hence, the depth increased by } 25 \% .}\end{array}](https://img.qammunity.org/2020/formulas/mathematics/middle-school/yz6sagfjtj878uca05fkts023b03turp82.png)