In January, the depth of a lake was 1,008 feet. In August, the depth of the lake was 806.4 feet. What is the percentage decrease of the depth of the lake from January to August?

20%

Step-by-step explanation:

First you have to take 1008 and subtract 806.4. Once you get that answer you put it into a division problem. So answer over the first number, being 1008. Then multiply that answer by 100. and that is your percentage.

x + 107

step-by-step explanation:

let's say that the number he had before the mistake was x. then, he will have 107 dollars more than this, so the answer is x + 107.