IIT JEE प्रश्न और उत्तर का अभ्यास करें
8प्र: The first synthetic fibre made by man was ____ ? 4556 15b5cc6e0e4d2b4197774eb2f
5b5cc6e0e4d2b4197774eb2f- 1Rayonfalse
- 2Terycottfalse
- 3Polyesterfalse
- 4Nylontrue
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उत्तर : 4. "Nylon"
व्याख्या :
Answer: D) Nylon Explanation:
प्र: What is the saddest fruit? 4549 05b5cc658e4d2b4197774bdc7
5b5cc658e4d2b4197774bdc7- 1Blackberriesfalse
- 2Strawberriesfalse
- 3Blueberriestrue
- 4Pineapplesfalse
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उत्तर : 3. "Blueberries"
व्याख्या :
Answer: C) Blueberries Explanation: Blueberries are the saddest fruits. Reason :: In English some colors are associated with feelings. Blue is associated with sadness. When you "feel blue" it means that you are feeling sad. Hence, as blueberries has blue in its name it indicates that that is the saddest fruit in logic.
प्र: A box contains 3 blue marbles, 4 red, 6 green marbles and 2 yellow marbles. If two marbles are picked at random, what is the probability that they are either blue or yellow ? 4531 05b5cc6dae4d2b4197774e8d7
5b5cc6dae4d2b4197774e8d7- 13/17false
- 24/21false
- 32/21true
- 45/17false
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उत्तर : 3. "2/21"
व्याख्या :
Answer: C) 2/21 Explanation: Given that there are three blue marbles, four red marbles, six green marbles and two yellow marbles. Probability that both marbles are blue = ³C₂/¹⁵C₂ = (3 x 2)/(15 x 14) = 1/35 Probability that both are yellow = ²C₂/¹⁵C₂ = (2 x 1)/(15 x 14) = 1/105 Probability that one blue and other is yellow = (³C₁ x ²C₁)/¹⁵C₂ = (2 x 3 x 2)/(15 x 14) = 2/35 Required probability = 1/35 + 1/105 + 2/35 = 3/35 + 1/105 = 1/35(3 + 1/3) = 10/(3 x 35) = 2/21
प्र: The current of a stream at 1 kmph. A motor boat goes 35 km upstream and back to the starting point in 12 hours. The speed of the motor boat in still water is ? 4523 05b5cc6dce4d2b4197774e9c4
5b5cc6dce4d2b4197774e9c4- 18 kmphfalse
- 26 kmphtrue
- 37.5 kmphfalse
- 45.5 kmphfalse
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उत्तर : 2. "6 kmph"
व्याख्या :
Answer: B) 6 kmph Explanation: Speed of the stream = 1Motor boat speed in still water be = x kmphDown Stream = x + 1 kmphUp Stream = x - 1 kmph[35/(x + 1)] + [35/(x - 1)] = 12x = 6 kmph
प्र: Solve the equation 122x+1 = 1 ? 4521 05b5cc6f4e4d2b4197774efd7
5b5cc6f4e4d2b4197774efd7- 1-1/2true
- 21/2false
- 31false
- 4-1false
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उत्तर : 1. "-1/2"
व्याख्या :
Answer: A) -1/2 Explanation: Rewrite equation as 122x+1 = 120 Leads to 2x + 1 = 0 Solve for x : x = -1/2
प्र: Amit can do a piece of work in 45 days, but Bharath can do the same work in 5 days less, than Amit, when working alone. Amit and Bharath both started the work together but Bharath left after some days and Amit finished the remaining work in 56 days with half of his efficiency but he did the work with Bharath with his complete efficiency. For how many days they had worked together? 4506 05b5cc7d0e4d2b419777511db
5b5cc7d0e4d2b419777511db- 16false
- 28true
- 39false
- 412false
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उत्तर : 2. "8"
व्याख्या :
Answer: B) 8 Explanation: AmitBharatNo.of Days4540Efficiency2.22Percent(=145)2.5 Percent(=140) Amit did the work in 56 days = 56×145×2=2845 Therefore, Rest work 17/45 was done by Amit and Bharath = 174517360 = 8 days ( since Amit and Bharath do the work in one day = 145+140=17360)
प्र: In India, planned economy is based on 4493 05b5cc6b5e4d2b4197774d568
5b5cc6b5e4d2b4197774d568- 1Mixed Economy Systemfalse
- 2Capitalist Systemfalse
- 3Gandhian Systemfalse
- 4Socialist Systemtrue
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उत्तर : 4. "Socialist System"
व्याख्या :
Answer: D) Socialist System Explanation:
प्र: Early morning after sunrise, Karthik was standing infront of his house in such a way that his shadow was falling exactly behind him. He starts walking straight and walks 5 metres. He turns to his left and walks 3 metres and again turning to his left walks 2 metres. Now in which direction is he from his starting point? 4487 05b5cc705e4d2b4197774f211
5b5cc705e4d2b4197774f211- 1Westfalse
- 2North-Easttrue
- 3Eastfalse
- 4South-Westfalse
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उत्तर : 2. "North-East"
व्याख्या :
Answer: B) North-East Explanation: Early morning suns rise at east, if his shadow falls exactly behind him that means he is facing towards east. now he walks 5mt towards east, then he turns left that means he facing towards north and walk 3mt and if he turn left then he is facing towards west and he walk only 3 kms thats why man is in north east direction from starting point.

