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 & Explanation
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
2×2 + x – 3 = 0
(2x + 3)(x – 1) = 0
x = 1 hr. [neglecting the -ve value of x]
View Answer Workspace Report Discuss in Forum
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 & Explanation
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
View Answer Workspace Report Discuss in Forum
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 & Explanation
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.
View Answer Workspace Report Discuss in Forum
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 & Explanation
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
View Answer Workspace Report Discuss in Forum
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 & Explanation
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.