A 200-Gallon Tank Is Full of a Solution Containing 25 $t = 0$

Multiple Choice

A 200-gallon tank is full of a solution containing 25 pounds of concentrate. Starting at time $t = 0$ , distilled water is added to the tank at a rate of 10 gallons per minute, and the well-stirred solution is withdrawn at the same rate. Find the time at which the amount of concentrate in the tank reaches 15 pounds. Round your answer to one decimal place.

A) $18.3 \mathrm {~min}$
B) $3.6 \mathrm {~min}$
C) $20.4 \mathrm {~min}$
D) $10.2 \mathrm {~min}$
E) $5.1 \mathrm {~min}$