A boy walking along a road at 3 km/hr is overtaken by a truck traveling at 40 km /hr. If the truck breaks down one km beyond where it passes the boy, how many minutes after the breakdown does the boy reach the truck?
a) 21 1/2 b) 20 c) 18 34/37 d) 18 26/43 e) 18 1/2
Rate problem!
This topic has expert replies
- Ashujain
- Master | Next Rank: 500 Posts
- Posts: 123
- Joined: Fri Apr 20, 2012 4:36 am
- Thanked: 29 times
- Followed by:1 members
Time taken by truck to travel 1km = 1/40 hrs = 60/40 mins = 1.5 minsbobdylan wrote:A boy walking along a road at 3 km/hr is overtaken by a truck traveling at 40 km /hr. If the truck breaks down one km beyond where it passes the boy, how many minutes after the breakdown does the boy reach the truck?
a) 21 1/2 b) 20 c) 18 34/37 d) 18 26/43 e) 18 1/2
Time taken by boy to travel 1km = 1/3 hrs = 60/3 mins = 20 mins
Therefore, the boy will reach the truck in 20-1.5 = 18.5 mins [spoiler](E)[/spoiler]
-
- Senior | Next Rank: 100 Posts
- Posts: 82
- Joined: Fri Nov 04, 2011 12:35 am
- Followed by:2 members
In my opinion the solution provided by Ashujain is good and here is mine
First of all,
The Time taken by truck to travel a km = 1/40 hrs = 60/40 mins = 1.5 mins
Time taken by the boy to travel 1km = 1/3 hrs = 60/3 mins = 20 mins
Therefore, the boy will reach the truck in 20 - 1.5 = 18.5 mins
This is the simplest method I think.
What are Perpendicular Lines
First of all,
The Time taken by truck to travel a km = 1/40 hrs = 60/40 mins = 1.5 mins
Time taken by the boy to travel 1km = 1/3 hrs = 60/3 mins = 20 mins
Therefore, the boy will reach the truck in 20 - 1.5 = 18.5 mins
This is the simplest method I think.
What are Perpendicular Lines