Aptitude - Boats and Streams - Discussion
Discussion Forum : Boats and Streams - General Questions (Q.No. 8)
8.
A boat takes 90 minutes less to travel 36 miles downstream than to travel the same distance upstream. If the speed of the boat in still water is 10 mph, the speed of the stream is:
Answer: Option
Explanation:
Let the speed of the stream x mph. Then,
Speed downstream = (10 + x) mph,
Speed upstream = (10 - x) mph.
 |
36 | - | 36 | = | 90 |
| (10 - x) | (10 + x) | 60 |
72x x 60 = 90 (100 - x2)
x2 + 48x - 100 = 0
(x+ 50)(x - 2) = 0
x = 2 mph.
Discussion:
85 comments Page 8 of 9.
Rishabh said:
1 decade ago
How does it become (36)/(10-x)-(36)/(10+x)?
Abhinn said:
1 decade ago
Please explain what does 90 min less means?
Karthik said:
1 decade ago
Why we should convert min to hour anybody?
Guru said:
5 years ago
I am not getting this, please explain me.
(3)
Madhavan said:
10 years ago
Is there any other method to solve this?
Suchita said:
1 decade ago
I don't understand this, please help.
Arun said:
4 years ago
@Rohit.
Perfect explanation, Thanks.
Perfect explanation, Thanks.
(2)
Diwakar said:
8 years ago
1 mile = 1600 meters = 1.6 km.
Abc said:
1 decade ago
Because the unit is in hours.
Bhimu said:
1 decade ago
60 is to convert min to hour.
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