Related rates/Optimization problem. Please show how to solve the problem, not just the answer. Thank you!

1. A water trough is 2 feet deep and 10 feet long. It has a trapezoidal cross section with base lengths of 2 feet and 5 feet. If water enters the empty trough at a rate of 10 ft³/min, how fast is the water level rising when the water is 1 foot deep? Express your answer in in/min to three decimal places.

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