Quantitative Quiz
Hello Everyone,
This Post contains few questions on Boat and Stream which can be asked in various competitive exams. Practice makes a man perfect. Keep Practicing, Keep raising.
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(in hours) taken by the boat to go 68 km downstream ?
A- 2 B- 3 C- 4 D- 6
Ans: C
2- 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?
A- 3:8 B- 5:3 C- 8:3 D- 7:4
Ans: C Soln:
8 hr 48 = 8
48/60 = 8 4/5= 44/5 hr
Downstream speed= D , Upstream Speed= S
Acc to question
D* 4 = S * 44/5 == > D/S= 11/5
Need to find X/S == > {D+S}/2 / {D-S}/2
== > 11+5/ 11-5 = 16/6= 8:3
3-
A- 4 B- 5 C- 6 D- 10
Ans: B Soln:
x= 15 ,D=30
Using
D= t * (x^2- s^2)/2x
30= 4.5 * (225- s^2)/30
Or s^2= 225-200== >s=5 ans
4- A
boat running downstream covers a distance of 16 km in 2 hours while for
covering the same distance upstream, it takes 4 hours. What is the speed (in
kmph)of the boat in still water?
A- 4
B- 8 C- 6 D- CND
Ans: C Soln:
Ds= 16/2=8
Us=16/4= 4
X= (8+4)/2=6
5- 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 (in mph)is?
A- 2
B- 3 C- 5/2 D- 4
Ans: A Soln:
Acc to ques:
36/(10-s) -36/(10+s)= 90/60
1/(10-s) - 1/(10+s)= 1/24
== > S^2 + 48s- 100=0 == >s= -50, +2
== >s= 2 ans
6- A
man can row at 5 kmph in still water. If the velocity of current is 1 kmph and
it takes him 1 hour to row to a place and come back, how far is the place? (in
KM)
A- 2.4 B- 3.6 C- 2.8 D- 4.8
Ans: A Soln:
Using direct formula
D= 1 * (25- 1)/10== > 2.4
7- A boat covers a certain distance downstream in
1 hour, while it comes back in 1 1/2 hours. If the
speed of the stream be 3 kmph, what is the speed of the boat in still water?
(in kmph)
A- 15 B- 20 C- 30 D- 10
Ans: A Soln:
Let distance be x
Ds= x , Us= 2/3x
3= x-2x/3== >x= 18
Speed in still water= (X + 2/3x )/2= 15
8- A
man can row three-quarters of a kilometre against the stream in 11 1/4 minutes and down the
stream in 7 1/2 minutes. The
speed (in km/hr) of the man in still water is?
A- 5 B- 3 C- 4 D- 2
Ans: A Soln:
11 ¼ min= 45/4 min= 45*15 sec= 675 seconds
7 ½ min= 15/2 min= 15*30= 450 sec
Distance= 3/4 km = 750 m
Us= 750/675 , Ds= 750/450
Speed in still water = (Ds+Us)/2= 25/18 mps
= 25/18 * 18/5= 5 kmph
9- A man takes twice as long to
row a distance against the stream as to row the same distance in favour of the
stream. The ratio of the speed of the boat (in still water) and the stream?
A- 3:1 B- 2:3 C- 2:1 D- 1:2
Ans: A Soln:
{2x+x}/{2x-x}= 3/1ans ; x is upstream speed and 2x is downstream
speed.
10- A man rows to a place 48 km distant and come
back in 14 hours. He finds that he can row 4 km with the stream in the same
time as 3 km against the stream. The rate of the stream is? In kmph
A- 2 B- 2.5 C- 1 D- 1.5
Ans: C Soln:
let time be t hours
Acc to question
1/(4/t) + 1/(3/t)= 14/48
t {1/3 + 1/4) = 7/24
==>t= 1/2
Ds= 8 kmph , Us= 6 kmph == >s= (8-6)/2=
1kmph
Quiz Prepared By- Che Sir
Regards,
Classroom Team
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