# Related Rates question from Pure Mathematics 1 by Hugh Neil

There is a question in my Pure Maths book which seems to confuse me. Ive done the rest but somehow this question seems to confuse me I think enough info is not given.

A water tank has a rectangular base 1.5m by 1.2m. The sides are vertical and water is being added to the tank at a constant rate of 0.45m^3 per minute. At what rate is the depth of water in the tank increasing?

Every minute $0.45 \text{ m}^3$ of water is added. Since $1.5\times1.2 \text{ m}^2$ is the area of the base, $0.45 \text{ m}^3$ of water will have height $\dfrac{0.45 \text{ m}^3}{1.5\times1.2 \text{ m}^2}=0.25 \text{ m}$. Thus the required rate is $0.25 \text{ m min}^{-1}$.