Question

Lake Lopez had a water depth at its dam of 515 inches at the beginning of the year. During the rainy season, the water depth increased by 82 inches. Evaporation during a hot summer decreased the depth by 119 inches. What was the water depth at the end of the summer?

Answer 1

Beginning of the year= 515 inches

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Rain increases the water depth:

After rainy season = 515 + 82 = 597 inches

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Evaporation decreases the water depth:

After Hot Summer = 597 - 119 = 478 inches

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Answer: 478 inches

Answer 2

This question states that Lake Lopez began at a depth of 515 inches, then increased by 82 inches, then decreased by 119 inches. To model this, we will use addition for the increase and subtraction for the decrease; this will signify a positive/negative change in the depth. This can be modeled by the expression below:

515 + 82 - 119

597 - 119

478

Therefore, the water depth at the end of the summer was 478 inches.

Hope this helps!