Aptitude - Time and Distance - Discussion
Discussion Forum : Time and Distance - General Questions (Q.No. 8)
8.
The ratio between the speeds of two trains is 7 : 8. If the second train runs 400 km in 4 hours, then the speed of the first train is:
Answer: Option
Explanation:
Let the speed of two trains be 7x and 8x km/hr.
| Then, 8x = |  |
400 |  |
= 100 |
| 4 |
 x = |
|
100 | |
= 12.5 |
| 8 |
Speed of first train = (7 x 12.5) km/hr = 87.5 km/hr.
Discussion:
51 comments Page 4 of 6.
AKHILA MALKANI said:
2 years ago
Simple, just consider their ratios and equate :
S1:S2 = 7:8.
Let's consider x is the speed of train1;
x/8 = 7/88x= 700.
x= 700/8 = 87.5.
S1:S2 = 7:8.
Let's consider x is the speed of train1;
x/8 = 7/88x= 700.
x= 700/8 = 87.5.
(2)
Choden said:
4 years ago
@All.
The ratio is7:8::x:400.
Simply multiply extremes(400*7) and divide by 8x(mean).
400*7=2800÷8,
=350.
Now 350÷4=87.5.
The ratio is7:8::x:400.
Simply multiply extremes(400*7) and divide by 8x(mean).
400*7=2800÷8,
=350.
Now 350÷4=87.5.
(3)
Har said:
10 months ago
400/4 = 100 km/hr.
after this;
100/8 = 12.5 parts of the second train.
100 - 12.5 = 87.5 km/hr for the first train.
after this;
100/8 = 12.5 parts of the second train.
100 - 12.5 = 87.5 km/hr for the first train.
(4)
Mihir jack said:
1 decade ago
Let this try :
Assume 7:8 = 7/8 = 0.875
Now 0.875 % less speed than 2nd train ,
Now simple 0.875 *100 = 87.5 answer
Assume 7:8 = 7/8 = 0.875
Now 0.875 % less speed than 2nd train ,
Now simple 0.875 *100 = 87.5 answer
Anika said:
9 years ago
@Nasir.
I also did not understand how to solve the problem.
Can anyone find the solution for Nasir's question.
I also did not understand how to solve the problem.
Can anyone find the solution for Nasir's question.
Senthilkumaran S said:
2 years ago
Firstly, find the speed of the second Train = 400/4 = 100kmph.
7/8 = x/100,
x = 700/8,
x = 87.5.
7/8 = x/100,
x = 700/8,
x = 87.5.
(20)
Manish Singh said:
1 decade ago
7/8 = X/(400/4).
Now find the X,
It will come 87.5 KM/hr.
Here X is the speed of first train.
Now find the X,
It will come 87.5 KM/hr.
Here X is the speed of first train.
Naga said:
1 decade ago
How to solve the problems in less time please explain simple techniques or any tricks?
Jatin said:
10 years ago
How to solve problem which is given in ratio? Any specific formula for that?
(1)
Amala said:
1 decade ago
7:8
100kmph - 8
? - 7 ( so cross multiplication)
(7*100)/8=87.5
100kmph - 8
? - 7 ( so cross multiplication)
(7*100)/8=87.5
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