Aptitude - Boats and Streams - Discussion
Discussion Forum : Boats and Streams - General Questions (Q.No. 3)
3.
A boat running upstream takes 8 hours 48 minutes to cover a certain distance, while it takes 4 hours to cover the same distance running downstream. What is the ratio between the speed of the boat and speed of the water current respectively?
Answer: Option
Explanation:
Let the man's rate upstream be x kmph and that downstream be y kmph.
Then, distance covered upstream in 8 hrs 48 min = Distance covered downstream in 4 hrs.
 |
 |
x x 8 | 4 |  |
= (y x 4) |
| 5 |
| |
44 | x =4y |
| 5 |
| y = |
11 | x. |
| 5 |
 Required ratio = |
|
y + x | |
: | |
y - x | |
| 2 | 2 |
| = | |
16x | x | 1 | |
: | |
6x | x | 1 | |
| 5 | 2 | 5 | 2 |
| = | 8 | : | 3 |
| 5 | 5 |
= 8 : 3.
Discussion:
109 comments Page 3 of 11.
SAGOR said:
7 years ago
Let, the distance be = d.
Downsream speed= d/4,
Upstream speed= 5d/44,
So, d/4 : 5d/44.
11: 5.
Now, the speed of the boat =(11+5)/2.
= 8.
The speed of the current =(11-5)/2.
= 3.
So, ratio 8:3.
Downsream speed= d/4,
Upstream speed= 5d/44,
So, d/4 : 5d/44.
11: 5.
Now, the speed of the boat =(11+5)/2.
= 8.
The speed of the current =(11-5)/2.
= 3.
So, ratio 8:3.
(1)
Soumyarahul said:
6 years ago
First, convert the hours into a minute.
528 mints &240mts.
while simplifying the above minutes,
we get,
11 and 5.
11+5/2 :11-5/2.
8:3.
528 mints &240mts.
while simplifying the above minutes,
we get,
11 and 5.
11+5/2 :11-5/2.
8:3.
(1)
Sucharitha said:
5 years ago
8+4/5:4.
44:20.
Speed of the boat=64.
Water speed=24.
64:24.
8:3.
44:20.
Speed of the boat=64.
Water speed=24.
64:24.
8:3.
(1)
Anom said:
3 months ago
It was good. Thank you, @Anshul.
(1)
Pradeesh said:
1 decade ago
How can the y-x/2 become the current ratio?
Saranya said:
1 decade ago
Can you explain the process clearly?
Ashis said:
1 decade ago
As it is given to find out the ratio of speed of boat to speed of water w.r.to still water that is how required ratio is calculated.
You can find out from important formulae option i.e.
1/2(y-x)/1/2(y+x)
where y=speed at downstrem
x=speed at upstream.
You can find out from important formulae option i.e.
1/2(y-x)/1/2(y+x)
where y=speed at downstrem
x=speed at upstream.
Ravi said:
1 decade ago
I didn't understand how 8*4/5 will get.
Bharath said:
1 decade ago
Given is 8 hr 48min so converting min to hr
We have 48/60=4/5
We have 48/60=4/5
PHANI said:
1 decade ago
Thanks Ashis.
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