Wednesday, 6 August 2014

Time & Distance Quiz

1)A  person  covers  a  certain  distance  at  7kmph  .How  many  meters does  he  cover  in
2 minutes.
A) 14 kmph B) 7 kmph C) 2400m D) 1200m
Answer: Option C
Explanation:
Speed=72kmph=72*5/18 = 20m/s
Distance covered in 2min =20*2*60 = 2400m


2)If a man runs at 3m/s. How many km does he run in 1hr 40min
A) 18 km B) 7 km C) 12 km D) 17 km
Answer: Option A
Explanation:
Speed of the man = 3*18/5 kmph = 54/5kmph
Distance covered in 5/3 hrs=54/5*5/3 = 18km


3)A train covers a distance in 50 min ,if it runs at a speed of 48kmph on an average.The
speed at which the train must run to reduce the time of journey to 40min will be.
A) 18 kmph B) 60 kmph C) 30 kmph D) 50 kmph
Answer: Option B

Explanation:
Time=50/60 hr=5/6hr
Speed=48mph
distance=S*T=48*5/6=40km
time=40/60hr=2/3hr
New speed = 40* 3/2 kmph= 60kmph

 

4) Vikas can cover a distance in 1hr 24min by covering 2/3 of the distance at 4 kmph and
the rest at 5kmph.the total distance is?
A) 18 km B) 6 km C) 12 kmD) 17 km
Answer: Option B
Explanation:
Let total distance be S
total time=1hr24min
A to T :: speed=4kmph
diistance=2/3S
T to S :: speed=5km
distance=1-2/3S=1/3S
21/15 hr=2/3 S/4 + 1/3s /5
84=14/3S*3
S=84*3/14*3 = 6km

 

5)walking at ¾ of his usual speed ,a man is late by 2 ½ hr. the usual time is.
A) 4 B) 7 ½ C) 7 D) 5
Answer: Option B
Explanation:
Usual speed = S
Usual time = T
Distance = D
New Speed is ¾ S
New time is 4/3 T
4/3 T – T = 5/2
T=15/2 = 7 ½

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