21) The ratio between the speeds of two trains is 7: 8. If the second train runs 400 kms in 4 hours, then the speed of the first train i
- 1) 83.5 km/hr
- 2) 84.5 km/hr
- 3) 86.5 km/hr
- 4) 87.5 km/hr
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Ans. D
Explanation :
Let the speeds of two trains be 7X and 8X km/hr.
\begin{aligned}
8X = \frac{400}{4} \=> X = 12.5 Km/hr
\end{aligned}
So speed of first train is 12.5*7 = 87.5 km/hr
22) 2 trains starting at the same time from 2 stations 200 km apart and going in opposite direction cross each other at a distance of 110 km from one of the stations. What is the ratio of their speed
- 1) 11:9
- 2) 13:9
- 3) 17:9
- 4) 21:9
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Ans. A
Explanation :
We know total distance is 200 Km
If both trains crossed each other at a distance of 110 km then one train covered 110 km and other 90 km [110+90=200km]
So ratio of their speed = 110:90 = 11:9
23) 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
- 1) 200 Km
- 2) 222 Km
- 3) 224 Km
- 4) 248 Km
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Ans. C
Explanation :
Let time taken to travel the first half = x hr
Then time taken to travel the second half = (10 - x) hr
Distance covered in the the first half = 21x [because, distance = time*speed]
Distance covered in the the second half = 24(10 - x)
Distance covered in the the first half = Distance covered in the the second half
So,
21x = 24(10 - x)
=> 45x = 240
=> x = 16/3
Total Distance = 2*21(16/3) = 224 Km [multiplied by 2 as 21x was distance of half way]
24) 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. What is the duration of the flight
- 1) 3 hours
- 2) 2.4 hours
- 3) 1.4 hours
- 4) 1 hour
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Ans. D
Explanation :
Let the duration of the flight be x hours.
Then
\begin{aligned}
\frac{600}{x}-\frac{600}{x + \frac{1}{2}} = 200 \\frac{600}{x}-\frac{1200}{2x+1} = 200 \x(2x+1) = 3 \2x^2 + x - 3 = 0 \=> (2x+3)(x-1)=0
\end{aligned}
Neglecting the negative value for x we get x = 1
25) 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 to
- 1) 70.11 km/hr
- 2) 71.11 km/hr
- 3) 72.11 km/hr
- 4) 73.11 km/hr
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Ans. B
Explanation :
We know Time = Distance/speed
So total time taken =
\begin{aligned}
\left(\frac{160}{64}+\frac{160}{80}\right) \= \frac{9}{2} hours \\text{ Time taken for 320 Km = } \320*\frac{2}{9} = 71.11 km/hr
\end{aligned}
26) Approx __ % of Indian population is still Agriculturis
- 1) 46%
- 2) 50%
- 3) 58%
- 4) 64%
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27) Contribution of agriculture to Gross National Product is approximately
- 1) 14%
- 2) 15%
- 3) 16.5%
- 4) 17.5%
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28) How much population is living below poverty line in India
- 1) Approx 24%
- 2) Approx 25%
- 3) Approx 26%
- 4) Approx 27%
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29) The best indicator of economic development of any country is
- 1) Its agriculture
- 2) Its transport
- 3) Its gross production
- 4) Its per capita income
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30) What is the mainstay of Indian economy
- 1) Manufacturing
- 2) Business
- 3) Public sector
- 4) Agriculture
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