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

70 km/hr
75 km/hr
84 km/hr
87.5 km/hr

```Answer

Answer: Option  D Explanation:Let the speeds of two trains be 7x and 8x km/hr.
then 8x = 400/4 = x = 100/8 = 12.5
speed of first train = (7*12.5 = 87.5 km/hr ```

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42.  A truck covers a distance of 550 meters in 1 minutes whereas a bus covers a distance of 33 kilometers in 45 minutes. The ratio of their speeds is?

3:4
4:3
3:5
50:3

```Answer

Answer: Option  A Explanation:Ratio of speeds = (550/60*18/5) :(33/45*60) = 33:44 = 3:4. ```

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43.  one of the two buses completes a journey of 300 km in 7 1/2 hours and the other a journey of 450 km in 9 hours. the ratio of their average speeds is?

2:3
3:4
4:5
8:9

```Answer

Answer: Option  C Explanation:Ratio of speeds = (300*2/15) : (450/9) = 40: 50 = 4:5. ```

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44.  A car is running at a speed of 108 km. What distance will it cover in 15 seconds?

45 meters
55 meters
450 meters
none of these

```Answer

Answer: Option  C Explanation:Speed = 108 km = (108*5/18) m/sec = 30 m/sec.
therefore distance covered in 15 sec. = (30*15) m = 450 m.
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45.  How long will a boy take to run round a square field of side 35 meters, if he runs at the rate of 9 km/hr?

50 sec
52 sec
54 sec
56 sec

```Answer

Answer: Option  D Explanation:Speed = 9 km/hr = (9* 5/18) m/sec = 5/2 m/sec.
distance = (35*4) m = 140m.
therefore time taken =(140*2/5) sec = 56 sec. ```

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