Answer: The scale is 5cm/m (5 cm in the drawing are equivalent to 1 meter on the actual pit)
Explanation:
When we have an original measure M, and we redraw it with a new scale, where the new measure is m, the scale used is equal to:
scale = m/M.
In this case, we know that:
The pit is 3m, by 5m
and the drawing to scale is 15cm by 25cm
(15cm is the rescaled version of the 3m side, and 25cm is the rescaled version of the 5m side)
Using the equation above, we can find that the scale is:
Scale = 15cm/3m = 5cm/m
and, if we use the other side, we get:
Scale = 25cm/5m = 5cm/m
Both calculations give the same scale, as expected.
Then the scale is 5cm/m, which means that 5 centimeters in the drawing are equivalent to one meter in the real pit.