IIT JEE प्रश्न और उत्तर का अभ्यास करें

प्र: In three coloured boxes - Red, Green and Blue, 108 balls are placed. There are twice as many balls in the green and red boxes combined as there are in the blue box and twice as many in the blue box as there are in the red box. How many balls are there in the green box ? 3129 0

  • 1
    76
    सही
    गलत
  • 2
    54
    सही
    गलत
  • 3
    64
    सही
    गलत
  • 4
    48
    सही
    गलत
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उत्तर : 2. "54"
व्याख्या :

Answer: B) 54 Explanation: Let R, G and B represent the number of balls in red, green and blue boxes respectively. Then, . R + G + B = 108 ...(i), G + R = 2B ...(ii) B = 2R ...(iii) From (ii) and (iii), we have G + R = 2x 2R = 4R or G = 3R. Putting G = 3R and B = 2R in (i), we get: R + 3R + 2R = 108 6R = 108 R = 18. Therefore Number of balls in green box = G = 3R = (3 x 18) = 54.

प्र: Which gymnospermic plant cures rheumatism? 3124 0

  • 1
    Ephedra
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  • 2
    Pinus
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  • 3
    Araucaria
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  • 4
    Gnetum
    सही
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उत्तर : 4. "Gnetum"
व्याख्या :

Answer: D) Gnetum Explanation: Oil from Gnetum spp a gymnosperm belonging to the family Gnetaceae is used to relieve the effects of rheumatism The lianas and shrubs of Gnetum are found in the rain forests of the western ghats.

प्र: A, B, C and D enter into partnership. A subscribes 1/3 of the capital B 1/4, C 1/5 and D the rest. How much share did A get in a profit of Rs.2490 ? 3119 0

  • 1
    Rs. 820
    सही
    गलत
  • 2
    Rs. 830
    सही
    गलत
  • 3
    Rs. 840
    सही
    गलत
  • 4
    Rs. 850
    सही
    गलत
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उत्तर : 2. "Rs. 830"
व्याख्या :

Answer: B) Rs. 830 Explanation: Let the total amount in the partnership be 'x'.Then A's share = x/3B's share = x/4C's share = x/5D's share = x - (x/3 + x/4 +x/5) = 13x/60 A : B : C : D = x/3 : x/4 : x/5 : 13x/60 = 20 : 15 : 12 : 13 A's share in the profit of Rs. 2490 = 20 (2490/60) = Rs. 830.

प्र: Three taps P, Q and R can fill a tank in 12 hrs, 15 hrs and 20 hrs respectively. If P is open all the time and Q and R are open for one hour each alternately, starting with Q, then the tank will be full in how many hours ? 3115 0

  • 1
    9 hrs
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  • 2
    7 hrs
    सही
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  • 3
    13 hrs
    सही
    गलत
  • 4
    11 hrs
    सही
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उत्तर : 2. "7 hrs"
व्याख्या :

Answer: B) 7 hrs Explanation: Given, P can fill in 12 hrs Q can fill in 15 hrs R can fill in 20 hrs => Volume of tank = LCM of 12, 15, 20 = 60 lit => P alone can fill the tank in 60/12 = 5 hrs => Q alone can fill the tank in 60/15 = 4 hrs => R alone can fill the tank in 60/20 = 3 hrs Tank can be filled in the way that (P+Q) + (P+R) + (P+Q) + (P+R) + .... => Tank filled in 2 hrs = (5+4) + (5+3) = 9 + 8 = 17 lit => In 6 hrs = 17 x 6/2 = 51 lit => In 7th hr = 51 + (5+4) = 51 + 9 = 60 lit => So, total tank will be filled in 7 hrs.

प्र: Look at the series : 3, 7, 24, 11, __, 19, 19,... What number should fill the blank ? 3114 0

  • 1
    15
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  • 2
    13
    सही
    गलत
  • 3
    21
    सही
    गलत
  • 4
    16
    सही
    गलत
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उत्तर : 1. "15"
व्याख्या :

Answer: A) 15 Explanation: Two series alternate here, with every third number following a different pattern.In the main series, 4 is added to each number to arrive the next.In alternate series, 5 is subtracted from each number t arrive the next number.Here in the main series 3 + 4 = 77 + 4 = 1111 + 4 = 1515 + 4 = 19 In alternate series 24 - 5 = 1919 - 5 = 14...

प्र: Play is to actor as concert is to 3109 0

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    Musician
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  • 2
    percussion
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  • 3
    symphony
    सही
    गलत
  • 4
    piano
    सही
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उत्तर : 1. "Musician"
व्याख्या :

Answer: A) Musician Explanation: An actor performs in a play. A musician performs at a concert. Choices b, c, and d are incorrect because none is people who perform.   Hence, Play is to actor as concert is to Musician.

प्र: The number of permutations of the letters of the word 'MESMERISE' is  ? 3107 0

  • 1
    9!/(2!)^{2}x3!
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  • 2
    9! x 2! x 3!
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    गलत
  • 3
    0
    सही
    गलत
  • 4
    None
    सही
    गलत
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उत्तर : 1. "9!/(2!)^{2}x3!"
व्याख्या :

Answer: A) 9!/(2!)^{2}x3! Explanation: n items of which p are alike of one kind, q alike of the other, r alike of another kind and the remaining are distinct can be arranged in a row in n!/p!q!r! ways.The letter pattern 'MESMERISE' consists of 10 letters of which there are 2M's, 3E's, 2S's and 1I and 1R.Number of arrangements = 9!(2!)2×3!

प्र: Which best describes Genes? 3105 0

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    long, double chains of nucleic acids.
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  • 2
    long, single chains of amino acids.
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  • 3
    long, single chains of nucleic acids.
    सही
    गलत
  • 4
    long, double chains of amino acids.
    सही
    गलत
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उत्तर : 1. "long, double chains of nucleic acids."
व्याख्या :

Answer: A) long, double chains of nucleic acids. Explanation: Gene is a segment of chromosomal DNA or a sequence of DNA or RNA that codes for a molecule that has a function. It is the basic physical and functional unit of heredity.   As genes are made up of DNA it impies that they are long, double chains of nucleic acids as DNA is made of nucleic acids.

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