applying rates, ratios, proportions, and percents?

Question

a river is flooded and the height of the water is riseing. the levee along the river is 30 ft high and the workers are buildingit higher at a rate of 1/2 foot per hour. teh water height is 28 ft and it is rising 3/4 foot each hour. when will the water reach the top od the levee and why

Answer 1

The existing difference of height between the top of the levee and river water level
=30-28=2 ft
net rising of water-level/hour=3/4 -1/2 =1/4ft
Water will reach the top of the levee just in
(2divided by 1/4 or)8 hours

Answer 2

Levee = 30 +.5t feet where t is time in hours
Water level = 28 + .75t
30+.5t = 28 + .75t
2 = .25t
8 = t
The water will overflow the levee after 8 hours.

Answer 3

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