Aptitude - Races and Games - Discussion
Discussion Forum : Races and Games - General Questions (Q.No. 7)
7.
In 100 m race, A covers the distance in 36 seconds and B in 45 seconds. In this race A beats B by:
Answer: Option
Explanation:
| Distance covered by B in 9 sec. = |  |
100 | x 9 |  m |
= 20 m. |
| 45 |
A beats B by 20 metres.
Discussion:
13 comments Page 1 of 2.
Madhu said:
3 years ago
Lets time ratio is =
A : B A : B
36:45 => 4:5.
The speed ratio is;
A : B
5 : 4.
If a completes 100 with 5 units of speed, then B completes 80 with 4 units of speed.
A : B A : B
36:45 => 4:5.
The speed ratio is;
A : B
5 : 4.
If a completes 100 with 5 units of speed, then B completes 80 with 4 units of speed.
(1)
Sheth said:
4 years ago
Time ratio = 36:45 = 4:5.
Speed ratio = 5:4.
when A complete 5 B complete 4.
A complete 100 B complete 100*4/5 = 80m so A beat B by 20m.
Speed ratio = 5:4.
when A complete 5 B complete 4.
A complete 100 B complete 100*4/5 = 80m so A beat B by 20m.
(2)
Purushotham Reddy said:
6 years ago
20P---28P------100P.
A---- B ---- C.
Here, the difference between B and c is 8 points when you calculate only for 80 Points (from B to 100).
So 8 Points - 80 Points.
But we need for 100 points.
Then 8p -80p.
10P-100P.
Hope you understand.
A---- B ---- C.
Here, the difference between B and c is 8 points when you calculate only for 80 Points (from B to 100).
So 8 Points - 80 Points.
But we need for 100 points.
Then 8p -80p.
10P-100P.
Hope you understand.
Sana said:
7 years ago
Common time difference between A and B is =(45-36)=9sec.
Now, B travel distance 100m in 45sec.
So
45sec ----------> 100m
9sec ------------> (9/45)*100=20m.
This 20m is actual distance between A and B or A beat by B in 20m .
Now, B travel distance 100m in 45sec.
So
45sec ----------> 100m
9sec ------------> (9/45)*100=20m.
This 20m is actual distance between A and B or A beat by B in 20m .
(1)
T.somadatta said:
7 years ago
Speed of A = 100 (distance) /36 (Time) = 2.78 m/s.
Speed of B = 100 (distance) /45 (Time) = 2.22 m/s.
Difference in speed between A & B = 0.56 m/s < i.e. 2.78-2.22 m/s>.
Hence in 36 seconds in which A finishes the race, B will cover 2.22*36 = 80 meters.
So, A finishes the race 20m ahead of B.
Speed of B = 100 (distance) /45 (Time) = 2.22 m/s.
Difference in speed between A & B = 0.56 m/s < i.e. 2.78-2.22 m/s>.
Hence in 36 seconds in which A finishes the race, B will cover 2.22*36 = 80 meters.
So, A finishes the race 20m ahead of B.
Student said:
9 years ago
That's a great help thanks a lot!
Santhosh said:
9 years ago
36/45*100 = 80.
100-80 = 20.
100-80 = 20.
NoName said:
10 years ago
A 1sec - (100/36) m.
B 1sec - (100/45) m.
1sec - A is ahead by (100/36-100/45) = 5/9 m.
So, in 36s A is ahead by (5/9*36) = 20 m.
B 1sec - (100/45) m.
1sec - A is ahead by (100/36-100/45) = 5/9 m.
So, in 36s A is ahead by (5/9*36) = 20 m.
Mridul Chakraborty said:
1 decade ago
Detailed solution for easier interpretation :
Speed of A = 100 (distance)/36 (Time) = 2.78 m/s.
Speed of B = 100(distance)/45(Time) = 2.22 m/s.
Difference in speed between A & B = 0.56 m/s < i.e. 2.78-2.22 m/s>
Hence in 36 seconds in which A finishes the race, B will cover 2.22*36 = 80 meters.
So A finishes the race 20m ahead of B.
Speed of A = 100 (distance)/36 (Time) = 2.78 m/s.
Speed of B = 100(distance)/45(Time) = 2.22 m/s.
Difference in speed between A & B = 0.56 m/s < i.e. 2.78-2.22 m/s>
Hence in 36 seconds in which A finishes the race, B will cover 2.22*36 = 80 meters.
So A finishes the race 20m ahead of B.
Marimuthu said:
1 decade ago
In 36 seconds B covers (100/45)*36 = 80 meters.
In 36 seconds A covers 100 meters.
So A beat B by 20 meters.
In 36 seconds A covers 100 meters.
So A beat B by 20 meters.
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