39 persons can repair a road in 12 days, working 5 hours a day. In how many days will 30 persons, working 6 hours a day, complete the work?
Answer: B
Let the required number of days be x.
Less persons, More days (Indirect Proportion)
More working hours per day, Less days (Indirect Proportion)
Persons30:39Working hours/day6:5⋮⋮ 12:x
=> 30 * 6 * x = 39 * 5 * 12
=> x= 13
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If 7 spiders make 7 webs in 7 days, then 1 spider will make 1 web in how many days?
Answer: C
Let the required number days be x.
Less spiders, More days (Indirect Proportion)
Less webs, Less days (Direct Proportion)
Spiders1:7Webs7:1⋮⋮ 7:x
=> 1 * 7 * x = 7 * 1 * 7
=> x= 7
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In a camp, there is a meal for 120 men or 200 children. If 150 children have taken the meal, how many men will be created to with the remaining meal?
Answer: B
No answer description available for this question.
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A 100 m long 3 m high and 30 cm wide wall is built by 30 men, 20 women and 50 children working 9 hours a day in 20 days. How long a wall 1.5 m high 30 cm wide can be built by 15 men, 25 women and 35 children working 2 hour a day in 15 days (given men, women and children are equally efficient)?
Answer: B
Earlier dimensions of the wall = 100 × 3 × 0.30.
New dimensions = L × 1.5 × 0.3.
∴ As men, women and children are given to be equally efficient, so in the first case, the total number of persons is 100 (i.e. 30 + 20 + 50) and the same in the second case is 75 (15 + 25 + 35).
Length of wall = L = (75x100) x (2x9) x (15x20) x (100 x 3 x 3 x 0.3)/(1.5 x 0.3) ⇒ L = 25 m.
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If the price of 6 toys is Rs. 264.37, what will be the approximate price of 5 toys?
Answer: D
No answer description available for this question.
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An industrial loom weaves 0.128 metres of cloth every second. Approximately, how many seconds will it take for the loom to weave 25 metres of cloth?
Answer: B
No answer description available for this question.
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36 men can complete a piece of work in 18 days. In how many days will 27 men complete the same work ?
Answer: A
Less Men, means more Days {Indirect Proportion}
Let the number of days be x then,
27 : 36 :: 18 : x
[Please pay attention, we have written 27 : 36 rather than 36 : 27, in indirect proportion, if you get it then chain rule is clear to you :)]
=>27x = 36 * 18
=> x = 24
So 24 days will be required to get work done by 27 men.
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Some persons can do a piece of work in 12 days. Two times the number of such persons will do half of that work in
Answer: D
Let x men can do the in 12 days and the required number of days be z
More men, Less days [Indirect Proportion]
Less work, Less days [Direct Proportion ]
men2x:xwork1:12 :: 12 : z
∴2x×1×z=x×12×12
⇒z=3
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A certain number of men can finish a piece of work in 100 days. If there were 10 men less, it would take 10 days more for the work to be finished. How many men were there originally?
Answer: D
Originally let there be x men.
Less men, More days (Indirect Proportion)
Therefore, (x-10) : x :: 100 :110
=> (x - 10) * 110 = x * 100 => x= 110
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A man can walk a certain distance at a uniform speed in 100 days. How long will it take him to cover twice the distance at half the normal speed?
Answer: E
Earlier time = 100 days.
Distance is doubled and speed is reduced to half. ∴ time will become 2 × 2 i.e. 4 times.
Hence now it will take 100 × 4 = 400 days.
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