# 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

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

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

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

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

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