Answer:
The old tower has 150 steps
Explanation:
Let the number of steps in the old tower be m
Mathematically, time = distance/speed
In this case, the distance is the number of steps while the speed is the rate of climbing or descending
For climbing, time spent = m/3
For descending time spent = m/2
Since it took her 25 longer when descending;
This means that;
m/2 - m/3 = 25
(3m-2m)/6 = 25
m/6 = 25
m = 6 * 25
m = 150 steps