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:
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 5 of 7.
Gayu said:
3 years ago
Someone help me to understand the solution, please.
(3)
Roneet Jena said:
10 years ago
[(450-30x)+(450+30x)]/(225-x^2) = [900/(225-x^2)].
Darshana Jain said:
9 years ago
Thank you very much for the given explanation.
Sneha said:
9 years ago
How you people got 9/2? Please explain that.
Sourabh said:
1 decade ago
Very well Explained Seetha ...Thank you.....
Sunil sharma, kaverinagar said:
1 decade ago
How can you multiply in place of addition ?
Vinay said:
1 decade ago
How can calculate distance of upstream ?
Asha said:
1 decade ago
How can calculate distance of upstream ?
Jagu said:
1 decade ago
How we get 9/2 there please tell me.
Rajesh kumar said:
1 decade ago
-x2+225=200
=>x2=25
=>x=5km/hr
=>x2=25
=>x=5km/hr
Post your comments here:
Quick links
Quantitative Aptitude
Verbal (English)
Reasoning
Programming
Interview
Placement Papers