Question

1) The depth of a lake in Lowell changes over time due to rainfall and evaporation. A few months ago, the depth was 70 feet. Currently, the depth is 63 feet. By what percent has the depth of the lake decreased?

Answer 1

To find the percentage decrease, we will simply use the the formula;

new depth - original depth /original depth x100%

new depth =63 feet

original depth = 70 feet

63 - 70 / 70 x100%

-7/70 x100%

= -10% or 10% decrease.