Aptitude - Boats and Streams - Discussion

Discussion Forum : Boats and Streams - General Questions (Q.No. 4)
4.
A motorboat, whose speed in 15 km/hr in still water goes 30 km downstream and comes back in a total of 4 hours 30 minutes. The speed of the stream (in km/hr) is:
4
5
6
10
Answer: Option
Explanation:

Let the speed of the stream be x km/hr. Then,

Speed downstream = (15 + x) km/hr,

Speed upstream = (15 - x) km/hr.

30 + 30 = 4 1
(15 + x) (15 - x) 2

900 = 9
225 - x2 2

9x2 = 225

x2 = 25

x = 5 km/hr.

Video Explanation: https://youtu.be/lMFnNB3YQOo

Discussion:
63 comments Page 6 of 7.

Monika said:   7 years ago
Thank you all for giving the answer.
(3)

John said:   1 decade ago
What happen to the 900 and the 2?

Lakki said:   10 years ago
Any shortcut method for this sum?

Praveenbehera said:   8 years ago
Good explanation @Seetha. Thanks.

Riaan said:   1 decade ago
What dou mean by still water?

Rajesh said:   1 decade ago
How we will getting 30 sir?

Varun said:   1 decade ago
How there 41/2 will came?

Srinivas said:   8 years ago
Nice explanation @Seetha.

Geetha said:   7 years ago
How 900 came? Explain.
(1)

Abhishek said:   1 decade ago
Thank You...!

Seetha


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