Problema Solution

In January, the depth of a lake was 1,099 feet. In August, the depth of the lake was 659.4 feet. What is the percentage decrease of the depth of the lake from January to August?

Answer provided by our tutors

The drop is 1099-659.4.  As a percentage of the drop, we divide the drop by the original depth and multiply by 100 to convert the decrease into a percentage:

100*(1099-659.4)/1099

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40

So a 40% drop in depth occurred from January to August.