if mohit drives a birke at the rate of 24 km/hr ,he reaches his destination 5min too late; if he drives at rate of 30 km/hr ,he reacges his destination 4min too soon .how far is his destination?
Answers
Answer:
Step-by-step explanation:
case 1) Speed = 24km/h
destination = 5min late
case 2) speed = 30km/h
destination = 4min fast
speed = distance/time
distance = speed*time
d/24km/h - d/30km/h = 9min/60min
L.C.M of 24 and 30 = 120
5d-4d/120 = 9/60
1d/120 = 9/60
cross multiply
9*120 = 1d*60
9*120 = 60d
9*120/60 = d
d = 4.5km
therefore, his destination is 4.5km far.
Mohit drives the bike at the rate of 24 km/hr
He reached 5 min late.
When he drove at 30 km/hr he reached 4 min late.
Difference between the time = 5 min + 4 min
= 9 min
= 9/60 hr
= 3/20 hr...........................(1)
Calculating the destination
Speed = distance/time
Let the distance be x and second time be t
First time is t + 9 because he took more time [ see 1 ]
In the first case :
24 = x/( t + 3/20 )
==> 24 ( t + 3/20 ) = x .............................(2)
In the second case :
30 = x/t
==> 30 t = x ..............................(3)
From (2) and (3) we get :
==> 24 ( t + 3/20 ) = 30 t
==> 24 t + 72/20 = 30 t
==> 6 t = 72/20
==> t = 12/20 hr
Distance = speed × time
= 30 km/hr × 12/20 hr
==> 18 km
The distance will be 18 km
Hope it helps u
___________________________________________________________________