A takes 4 hours more than B to cover a distance of 80 km. If A doubles his speed, he takes 1.5 hour more than B to cover 80 km. To cover a distance of 160 km, how much time (in hour) will B take travelling at the same speed?
Answer & explanation
Correct answer: option 2
SA (Speed of A) = 1 : 2
TA (time of A) = 2 : 1 ... (Diff. 1 → ×2.5 → 2.5 hours)
↓
×2.5
↓
5 hours
as A takes 4 hours more than B to travel 80 km, i.e. B takes only 1 hour so SB = 80 km/h
t = \(\frac{160}{80}\) = 2 hours