IndiaBIX

Aptitude - Time and Distance - Discussion

Discussion Forum : Time and Distance - General Questions (Q.No. 13)
Time and Distance
13.
It takes eight hours for a 600 km journey, if 120 km is done by train and the rest by car. It takes 20 minutes more, if 200 km is done by train and the rest by car. The ratio of the speed of the train to that of the cars is:
2 : 3
3 : 2
3 : 4
4 : 3
Answer: Option
Explanation:

Let the speed of the train be x km/hr and that of the car be y km/hr.

Then, 120 + 480 = 8       1 + 4 = 1 ....(i)
x y x y 15

And, 200 + 400 = 25     1 + 2 = 1 ....(ii)
x y 3 x y 24

Solving (i) and (ii), we get: x = 60 and y = 80.

Ratio of speeds = 60 : 80 = 3 : 4.

Discussion:
84 comments Page 5 of 9.
Deep said:   10 years ago
Can anyone explain it properly how we got 1/24?
Abi said:   9 years ago
200/x + 400/y = 25/3.
200 (1/x + 2/y) = 25/3.

1/x + 2/y = 25/3 * 200 (multiply 3 * 200).
1/x + 2/y = 25/600.
1/x + 2/y = 1/24.

By solving this, we get 3 : 4.
(1)
Vikash said:   9 years ago
Change 20 min in an hour then add 8 because take more time we get 25/3.
Sathish said:   9 years ago
How 120/x + 480/y = 8?
Soumitra said:   9 years ago
It takes more 20 min. It means 8hr + 20 min. Now convert into hr then it comes 20/60= 1/3. So time is 8hr+1/3hr= 25/3 hr.
(2)
Subash said:   9 years ago
I can't understand. How to get eqn (1) and eqn (2)? Anyone can explain full steps?
Gopikrishna said:   9 years ago
How you get 1/15?

Please answer me.
Pradeep said:   9 years ago
In first equation divide both sides by 120 then we get 1/15.

120/x + 480/y = 8,
1/x + 4/y = 8/120,
= 1/15.
Namita said:   9 years ago
How, from where that 1/15 came?
(1)
Liton das said:   8 years ago
25/3 how did it convert to 1/24?

Please explain.
Post your comments here:

Your comments will be displayed after verification.

Quick links
Quantitative Aptitude
Verbal (English)
Reasoning
Programming
Interview
Placement Papers