# Aptitude - Boats and Streams - Discussion

### Discussion :: Boats and Streams - General Questions (Q.No.1)

1.

A boat can travel with a speed of 13 km/hr in still water. If the speed of the stream is 4 km/hr, find the time taken by the boat to go 68 km downstream.

 [A]. 2 hours [B]. 3 hours [C]. 4 hours [D]. 5 hours

Explanation:

Speed downstream = (13 + 4) km/hr = 17 km/hr.

 Time taken to travel 68 km downstream = 68 hrs = 4 hrs. 17

 Balaji said: (Mar 18, 2011) In the question they given the data that speed of boat 13 km/hr and speed of stream is 4 km/hr and they asked us to solve the time taken by the boat in down stream for a distance of 68 kms. we know as per the formula down stream means speed of boat + speed of stream therefore, down stream = 13+4=17 km/hr as per the problem we got to find time taken by boat to travel a distance of 68km down stream. we have formula that, time=distance/speed =68/17 =4 hours

 Manasa said: (Jun 12, 2011) Thanks Balaji.

 Geetha said: (Jun 16, 2011) Thanks for your explanation.

 Anshu said: (Apr 4, 2012) Total speed during downstream, Speed = 13kmph + 4 kmph = 17 kmph. Time = distance / speed = 4 hours. Hope this helps!

 Arun.D said: (Jun 3, 2013) Speed of boat in still water = 13km/hr. Speed of the stream = 4km/hr. Time taken by the boat to go 68 km downstream = ? Speed of boat in downstream = (13+4)km/hr. = 17km/hr. Time = distance/speed. = 68/17hr. = 4hr.

 Akash U. said: (Jan 25, 2014) (Total speed)downstream = Speed of boat + Speed of stream. Time = Distance/speed.

 Wangdeep Tamang said: (Mar 22, 2014) Speed in Still water = 13 km/h. Speed of the stream = 4 km/h. Downstream = 13+4 = 17km (speed in Still water + speed of the stream). Time Take = 68/17 = 4 hrs.

 Manikyam said: (Apr 7, 2015) How to know particularly which formula to use whether downstream or upstream? Bit confusing?

 Somya said: (May 27, 2015) It is given in the question to find time taken to go 68 km downstream.

 Srikanth said: (Jun 24, 2015) Downstream speed = a. Upstream speed = b. Stream speed = 1/2 (a-b)----Formula. Boat speed = 1/2 (a+b)-----Formula. Given boat speed = 13. Stream speed = 4. So 1/2(a+b)+1/2(a-b) = 13+4. ==> a=7. Given D = 68km. D = S*T. Ta = D/Sa. =>68/17. =>4. So time taken by the boat to go 68 km downstream is 4 hrs.

 Prassanna.S said: (Aug 19, 2015) Thanks for giving the correct answer.

 V!Cky said: (Sep 6, 2015) Use Speed = Distance /Time formula. Still in water u+v = 13+4 = 17. 68/17 = 4 km/hr.

 Roshan said: (Sep 12, 2015) Still water speed + Boat speed = Total speed (down stream). Time = Distance/Speed.

 Praveen said: (Oct 14, 2015) Still water means? How it has speed?

 Chetan said: (Dec 12, 2015) It means speed of boat in still water is 13 km/h.

 Laxmidhar said: (Dec 16, 2015) Sp of down stream = (13+4) = 17. Time taken = 68\17 = 4 hr.

 Csharad said: (Mar 19, 2016) Here any short cut method for this?

 Kiruthika said: (Jun 28, 2016) Given: Speed in still water U = 13 km/hr, Speed of stream V = 4 km/hr, Distance = 68 km, Time = ? Solution: Time = distance / U+V(downstream speed) => 68/17, => 4 hour.

 Sivananda said: (Jul 7, 2016) Super explanation @Balaji. Thanks.

 Avijit Das said: (Jul 24, 2016) Appropriate explanation, Thanks to all.

 Honey said: (Aug 10, 2016) Good explanation, Thanks to all.

 Gaurank Verma said: (Aug 25, 2016) Since ship is going downstream, Hence, Resultant speed = 13 + 4 = 17 km/h. Now, Time = distance / speed. ==> Time = 68/17 = 4hours. Therefore, the boat will take 4 hrs. To go 68 km downstream.

 Narayana Reddy said: (Sep 23, 2016) Thanks for providing the answer and explanation.

 Raj said: (Jan 19, 2017) Hi, please give me a solution for this question. "A man can row 8 kms in still water. If in a river flowing at 2 km an hour, it takes him 24 minutes to row to a place and come back, how far of is this place?"

 A.Santhosh said: (Apr 2, 2017) Boat -> a kmph& stream-> b kmph A= boat speed at still water B= water speed=rate of current=stream speed. Along with the flow, Dss(downstream speed) = a+b, Againist with the flow, Uss(upstream speed) = a-b. So, a + b = 13 + 4 = 17, Distance = 68 km, Time = Dist/Uss, T = 68/17 = 4hrs.

 Birla Jyothi Swaroop said: (Apr 27, 2017) Perfect Explanation, thank @Santhosh.

 Ardhendu Sikdar said: (Jun 17, 2017) 13+4 = 17km/hr. Now, 48/17 = 4hr.

 Mythu said: (Jul 26, 2017) Thanks for all your explanations.

 Elizabath said: (Mar 13, 2018) Give a clear explanation to get it.

 Sheetul said: (Sep 9, 2018) Thank you so much @Balaji.

 Gauravbagul said: (Nov 18, 2018) 13+4 = 17km/hr, For 1 hour he goes 17 km. Then for 68 km he takes 4 hrs.

 Md Abdul Khabir said: (Jul 30, 2019) Thank you all for explaining it clearly.

 Venky said: (Aug 1, 2019) Thanks to all for giving an explanation.

 Bhushan Roy said: (Sep 6, 2019) Thanks for the nice explanation.

 Hanumanthu Vinayakarao said: (Dec 7, 2019) Distance = speed / time. Then time = distace/ speed. Speed = boat speed+stream speed. Speed = 13+4=17 distance = 68. D = 68/17 = 4hrs.

 Tanisha said: (Jun 10, 2020) Thanks @Srikant.

 Hunde Namomsa said: (Feb 13, 2022) Thanks everyone for explaining the answer.