Aptitude - Time and Distance

Exercise :: Time and Distance - General Questions

6. 

In a flight of 600 km, an aircraft was slowed down due to bad weather. Its average speed for the trip was reduced by 200 km/hr and the time of flight increased by 30 minutes. The duration of the flight is:

A. 1 hour
B. 2 hours
C. 3 hours
D. 4 hours

Answer: Option A

Explanation:

Let the duration of the flight be x hours.

Then, 600 - 600 = 200
x x + (1/2)

600 - 1200 = 200
x 2x + 1

x(2x + 1) = 3

2x2 + x - 3 = 0

(2x + 3)(x - 1) = 0

x = 1 hr.      [neglecting the -ve value of x]


7. 

A man complete a journey in 10 hours. He travels first half of the journey at the rate of 21 km/hr and second half at the rate of 24 km/hr. Find the total journey in km.

A. 220 km
B. 224 km
C. 230 km
D. 234 km

Answer: Option B

Explanation:

(1/2)x + (1/2)x = 10
21 24

x + x = 20
21 24

15x = 168 x 20

x = 168 x 20 = 224 km.
15


8. 

The ratio between the speeds of two trains is 7 : 8. If the second train runs 400 km in 4 hours, then the speed of the first train is:

A. 70 km/hr
B. 75 km/hr
C. 84 km/hr
D. 87.5 km/hr

Answer: Option D

Explanation:

Let the speed of two trains be 7x and 8x km/hr.

Then, 8x = 400 = 100
4

x = 100 = 12.5
8

Speed of first train = (7 x 12.5) km/hr = 87.5 km/hr.


9. 

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

A. 35.55 km/hr
B. 36 km/hr
C. 71.11 km/hr
D. 71 km/hr

Answer: Option C

Explanation:

Total time taken = 160 + 160 hrs. = 9 hrs.
64 80 2

Average speed = 320 x 2 km/hr = 71.11 km/hr.
9


10. 

A car travelling with of its actual speed covers 42 km in 1 hr 40 min 48 sec. Find the actual speed of the car.

A.
17 6 km/hr
7
B. 25 km/hr
C. 30 km/hr
D. 35 km/hr

Answer: Option D

Explanation:

Time taken = 1 hr 40 min 48 sec = 1 hr 40 4 min = 1 51 hrs = 126 hrs.
5 75 75

Let the actual speed be x km/hr.

Then, 5 x x 126 = 42
7 75

x = 42 x 7 x 75 = 35 km/hr.
5 x 126