Ques. A Man travelled a distance of 61 km in 9 hours. He travelled partly on foot at 4 km/hr and partly on bicycle at 9 km/hr. What is the distance travelled on foot?

16 km

14 km

12 km

10 km

Answer And Explanation

Answer: Option A

Explanation:

Let the time in which he travelled on foot = x hour

Time for travelling on bicycle = (9 - x) hr

Distance = Speed * Time, and Total distance = 61 km

So,

4x + 9(9-x) = 61

=> 5x = 20

=> x = 4

So distance traveled on foot = 4(4) = 16 km

A man on tour travels first 160 km at 64 km/hr and the next 160 km at 80 km/hr. Find the average speed for first 320 km of tour.

70.11 km/hr

71.11 km/hr

72.11 km/hr

73.11 km/hr

Answer And Explanation

Answer: Option B

Explanation:

We know Time = Distance/speed

So total time taken =

(160/64+160/80)=92hours

Time taken for 320 Km

= 320∗2/9

=71.11km/hr

Robert is travelling on his cycle and has calculated to reach point A at 2 P.M. if he travels at 10 kmph, he will reach there at 12 noon if he travels at 15 kmph. At what speed must he travel to reach A at 1 P.M.?

9 km/hour

10 km/hour

11 km/hour

12 km/hour

Answer And Explanation

Answer: Option D

Explanation:

We need to calculate the distance, then we can calculate the time and finally our answer.

Lets solve this,

Let the distance travelled by x km

Time = Distance/Speed

x/10−x/15=2

[because, 2 pm - 12 noon = 2 hours]

3x−2x=60

x=60

Time=Distance/Speed

Time@10km/hr=60/10=6hours

So 2 P.M. - 6 = 8 A.M

Robert starts at 8 A.M.

He have to reach at 1 P.M. i.e, in 5 hours

So, Speed = 60/5 = 12 km/hr

A person travels from P to Q at a speed of 40 km/hr and returns by increasing his speed by 50%. What is his average speed for both the trips ?

44 km/hour

46 km/hour

48 km/hour

50 km/hour

Answer And Explanation

Answer: Option C

Explanation:

Speed while going = 40 km/hr

Speed while returning = 150% of 40 = 60 km/hr

Average speed =

2xy/(x+y)

=2∗40∗60/(40+60)

=4800/100

=48Km/hr