3. Amitabh covered a distance of 96 km two hours
faster than he had planned to. This he achieved by
travelling 1 km more every hour than he intended to
cover every 1 hour 15 minutes. What was the speed
at which Amitabh travelled during the journey?
(a) 16 km/h
(6) 26 km/h
(c) 36 km/h
(d) 30 km/h
Answers
Answer:
According to question
Let the speed Amitabh thought of be u and time be t
Thus
Total distance covered x = 96 Km
Thus
at 1st hour x = 1
at 2nd hour x = 2
and so on
Thus clearly u + 2 = 96 / 1
So u = 94
and
u = 96 / 1.25
u = 76.8
Answer:
Answer
He planned to cover x km in 1hr15min ( 60 75 m)→( 4 5 hr)
He actually covered (x+1) km in every hour.
Planned speed = 4 5
x = 5 4x km/h
Actual speed 1 x+1 =x+1km/hr
He reached the 96 km 2 hrs faster than his assumed speed.
∴ 5 4x
96 − x+1 96 =2
x 120 − x+1 96 =2
120(x+1)−96x=2x(x+1)
120x+120−96x=2x
2 +2x
2x 2 −22x−120=0
x 2 −11x−60=0
x 2 −15x+4x−60=0
x(x−15)+4(x−15)=0
x=15km/hr
Actual speed =x+1=16km/hr