Question

before the rain began,the water in a lake was 268 inches deep.the rain began and after four hours of rain,the lake was 274 inches deep.the rain continued for one more hour at the same intensity.what was the depth of the lake when the rain stopped?

Answer 1

$\frac{274-268}{4}=1.5 \\1.5+274=275.5$

The answer is $275.5$.