Aptitude - Races and Games - Discussion
Discussion Forum : Races and Games - General Questions (Q.No. 3)
3.
In a 500 m race, the ratio of the speeds of two contestants A and B is 3 : 4. A has a start of 140 m. Then, A wins by:
Answer: Option
Explanation:
To reach the winning post A will have to cover a distance of (500 - 140)m, i.e., 360 m.
While A covers 3 m, B covers 4 m.
| While A covers 360 m, B covers |  |
4 | x 360 |  m |
= 480 m. |
| 3 |
Thus, when A reaches the winning post, B covers 480 m and therefore remains 20 m behind.
A wins by 20 m.
Discussion:
14 comments Page 1 of 2.
ANUPCHERRY said:
4 years ago
A : B =140M.
3X + 4X =7X,
140/7 = 20M.
3X + 4X =7X,
140/7 = 20M.
(8)
Anand said:
6 years ago
Here is the simplest method,
Speed ratio is 3:4 SO let consider 3m & 4m for both A & B.
A travels 360 and B travels 500.
This means A takes 120 seconds and B takes 125 seconds.
5 seconds more than A is travelled by B.
In one B travels 4m.
So in 5 seconds, 5*4=20m.
B travels 20m more than A.
That is A win by 20m.
Speed ratio is 3:4 SO let consider 3m & 4m for both A & B.
A travels 360 and B travels 500.
This means A takes 120 seconds and B takes 125 seconds.
5 seconds more than A is travelled by B.
In one B travels 4m.
So in 5 seconds, 5*4=20m.
B travels 20m more than A.
That is A win by 20m.
(4)
Newstein Faraday . said:
1 decade ago
A has to travel 360 meters therefore Time =distance/ speed. So 360/3 = 120 seconds.
The same 120 seconds b has to travel so distance = speed x time = 4 x 120 = 480.
The remaining distance that b has to travel is 500-480 = 20.
The same 120 seconds b has to travel so distance = speed x time = 4 x 120 = 480.
The remaining distance that b has to travel is 500-480 = 20.
(1)
Ash said:
10 years ago
Speed is directly proportional to distance.
3/4 = (500-140)/(500-x).
3/4 = 360/(500-x).
Hence x = 20.
3/4 = (500-140)/(500-x).
3/4 = 360/(500-x).
Hence x = 20.
(1)
BKD said:
5 years ago
3/4 = (500-140)/x.
x = 480.
Thus, In 500 m race, A gives B by 20m i.e.500-480.
x = 480.
Thus, In 500 m race, A gives B by 20m i.e.500-480.
(1)
Kriti said:
1 decade ago
Hi, when 3:4 is the ratio of speeds how can we use it
as 3m and 4m for A and B resp.?
as 3m and 4m for A and B resp.?
Sudheer said:
1 decade ago
Hi kriti here speed and distance are directly proportinal. If his speed is 10km/hr he cover 10km distance. If speed is 20km/hr he can cover 20 km distance. Thus speed and distance are directly proportinal. So here distance ratios also become3:4. But the time ratio will become4:3 because time and speed are inversly proportinal.
Vamsi said:
1 decade ago
I didn't understand how it can be 4/3. ?
Malli said:
1 decade ago
Hai, my dout is same that of vamsi.
Why we had taken 4/3 in problem?
Why we had taken 4/3 in problem?
Manojit said:
1 decade ago
While A covers 3 m, B covers 4 m.
While A covers 1m, B covers 4/3 m.
While A covers 360 m, B covers (4/3* 360)m =480 m.
Here time is same in case of speed.we count different distance in same time.
While A covers 1m, B covers 4/3 m.
While A covers 360 m, B covers (4/3* 360)m =480 m.
Here time is same in case of speed.we count different distance in same time.
Post your comments here:
Quick links
Quantitative Aptitude
Verbal (English)
Reasoning
Programming
Interview
Placement Papers