Running at $$\frac{5}{4}$$ of his usual speed, an athlete improves his timing by 5 minutes. The time he usually takes to run the same distance is:
A. 30 min.
B. 28 min.
C. 25 min.
D. 23 min.
Answer: Option C
Solution (By Examveda Team)
When the athlete walks at $$\frac{5}{4}$$ of his usual speed then he takes $$\frac{4}{5}$$ of his usual time $$\left( {{\text{As}}\,\,{\text{Speed}}\, \propto \frac{1}{{{\text{Time}}}}} \right)$$ and he saves 5 minutes. → Usual time - $$\frac{4}{5}$$ × usual time = 5 minutes → $$\frac{1}{5}$$ × Usual time = 5 minutes Usual time = 25 minutes.This Question Belongs to Arithmetic Ability >> Speed Time And Distance
v1t1=v2t2
So vt=5v/4(t-5)
4t=5t-25
t=25min
Simple, Multiply the Numerator and denominator with the time provided.
Here, Time = 5 Min
So, 5*5 / 4*5 = 25 / 20
Numerator = Usual time=> (25)
Denominator = Late time =>(20).
clear