IIT JEE Practice Question and Answer

Q: Pipe A can fill a tank in 16 minutes and pipe B cam empty it in 24 minutes. If both the pipes are opened together after how many minutes should pipe B be closed, so that the tank is filled in 30 minutes  ? 3720 0

  • 1
    21 min
    Correct
    Wrong
  • 2
    24 min
    Correct
    Wrong
  • 3
    20 min
    Correct
    Wrong
  • 4
    22 min
    Correct
    Wrong
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Answer : 1. "21 min"
Explanation :

Answer: A) 21 min Explanation: Let the pipe B be closed after 'K' minutes. 30/16 - K/24 = 1 => K/24 = 30/16 - 1 = 14/16 => K = 14/16 x 24 = 21 min.

Q: Time taken by P alone to finish a work is 50% more than the time taken by P and Q together. Q is thrice as efficient as R. If Q and R together can complete the work in 22.5 days, then how many days will P alone take to complete the work ? 3715 0

  • 1
    17 days
    Correct
    Wrong
  • 2
    11 days
    Correct
    Wrong
  • 3
    15 days
    Correct
    Wrong
  • 4
    16 days
    Correct
    Wrong
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Answer : 3. "15 days"
Explanation :

Answer: C) 15 days Explanation: We know that Time is inversely proportional to Efficiency Here given time ratio of P & P+Q as P/P+Q = 150/100 = 3:2 Efficiency ratio of P & Q as P:Q = 2:1 ....(1) Given Efficiency ratio of Q & R as Q:R = 3:1 ....(2) From (1) & (2), we get P:Q:R = 6:3:1 P alone can finish the work in 22.5(3+1)/6 = 15 days.

Q: A watch gains 5 seconds in 3 minutes and was set right at 8 AM. What time will it show at 10 PM on the same day ? 3714 0

  • 1
    10 : 27 : 41 AM
    Correct
    Wrong
  • 2
    8 : 51 : 04 AM
    Correct
    Wrong
  • 3
    9 : 45 : 15 PM
    Correct
    Wrong
  • 4
    10 : 23 : 20 PM
    Correct
    Wrong
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Answer : 4. "10 : 23 : 20 PM"
Explanation :

Answer: D) 10 : 23 : 20 PM Explanation: The watch gains 5 seconds in 3 minutes = 100 seconds in 1 hour. From 8 AM to 10 PM on the same day, time passed is 14 hours. In 14 hours, the watch would have gained 1400 seconds or 23 minutes 20 seconds. So, when the correct time is 10 PM, the watch would show 10 : 23 : 20 PM

Q: If a trader sold two cars each at Rs. 325475 and gains 12% on the first and loses 12% on the second, then his profit or loss percent on the whole is ? 3712 0

  • 1
    1.44% loss
    Correct
    Wrong
  • 2
    14.4% loss
    Correct
    Wrong
  • 3
    0%
    Correct
    Wrong
  • 4
    14.4% profit
    Correct
    Wrong
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Answer : 1. "1.44% loss"
Explanation :

Answer: A) 1.44% loss Explanation: SP of each car is Rs. 325475, he gains 12% on first car and losses 12% on second car.In this case, there will be loss and percentage of loss is given by = [(profit%)(loss%)]/100 = (12)(12)/100 % = 1.44%

Q: Study of the sun is called 3690 0

  • 1
    Coronagraphy
    Correct
    Wrong
  • 2
    Seismography
    Correct
    Wrong
  • 3
    Helioseismology
    Correct
    Wrong
  • 4
    Heliography
    Correct
    Wrong
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Answer : 3. "Helioseismology"
Explanation :

Answer: C) Helioseismology Explanation: Helioseismology is the study of the solar interior using observations of waves on the Sun's surface. It has done much to improve our understanding of the interior of the Sun, testing the physical inputs used to model stellar interiors and providing a detailed map of the Sun's structure and internal rotation.

Q: निम्नलिखित में से किस स्मृति को ताज़ा करने की आवश्यकता है? 3683 6

  • 1
    DRAM
    Correct
    Wrong
  • 2
    ROM
    Correct
    Wrong
  • 3
    SRAM
    Correct
    Wrong
  • 4
    ऊपर के सभी
    Correct
    Wrong
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Answer : 1. "DRAM"
Explanation :

Answer: A) DRAM Explanation:

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Answer :
Explanation :

1. Answer : 2 Explanation : Productivity = Total production/area of Agr.land  Productivity of UP = [ (35000+30000+25000) / (30/100) ] = 300000   Productivity of MP = [ (30000+37500+27500) / (25/100) ] = 380000   Productivity of Bihar = [ (22500+27500+25000) / (20/100) ] = 375000  Productivity of Odisha = [ (22500+15000+10000) / (5/100) ]= 950000   Productivity of Haryana = [ (30000+25000+35000) / (8/100) ] = 1125000   Productivity of Punjab = [ (40000+35000+30000) / (12/100) ] = 875000  The Productivity of Haryana is the maximum.       2. Answer : 5   Explanation : Production of Punjab is maximum = 105000 tonnes      3. Answer : 3  Explanation : Production of Wheat in Punjab = 40000 tones Production of Maize in Odisha = 10000 tones Required % = (40000 - 10000)/100 = 300%      4. Answer : 4  Explanation : The ratio of prodution of Rice in Bihar to the production of Wheat in Haryana = 25000 tonnes : 25000 tonnes = 1 : 1       5. Answer : 1   Explanation : Income of MP from export of 40% of Rice at the rate of Rs.30 per kg = Rs.39crore Income of UP from export of 30% of Rice at the rate of Rs.32 per kg = Rs.28.8 crore  Required ratio = 39 : 28.8 = 390 : 288 = 65 : 48

Q: Study of teeth is called 3673 0

  • 1
    Pedagogy
    Correct
    Wrong
  • 2
    Ornithology
    Correct
    Wrong
  • 3
    Orthoepy
    Correct
    Wrong
  • 4
    Odontology
    Correct
    Wrong
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Answer : 4. "Odontology"
Explanation :

Answer: D) Odontology Explanation: The study or scientific study of the structure, development, and abnormalities of the teeth is called Odontology. The science that studies teeth and their surrounding tissues, especially the prevention and cure of their diseases is called Dentology.

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