Normal speed of a boat in still water is 4 times the speed of the river. The boat goes upstream from P to Q and takes 4 hrs. By what percent should the boat increase/decrease its speed if it’s required to reach P from Q in exactly 3 hours?
1
Increases by 20%
2
Increases by 25%
3
Decreases by 20%
4
Decreases by 25%
5
None of these