Answer:
25%
Step-by-step explanation:
Let v, t be the current average speed and the time taken to reach the school respectively.
As distance = speed x time, so,
distance, d=vt...(i)
Let V be the new average speed in order to to take 20% less time than t.
So, time taken with speed V = t-20% of t = t- 0.2t= 0.8t
As distance is constant, so
d= V(0.8t)= 0.8Vt
hBy using equation (i), we have
0.8Vt = vt
0.8 V = v
V= v/0.8=1.25v
Therefore, the percentage increase in the average speed =
=25%
Hence, the percentage increase in the average speed is 25%.