IIT JEE Practice Question and Answer

Q: 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 ? 2740 0

  • 1
    9 hrs
    Correct
    Wrong
  • 2
    7 hrs
    Correct
    Wrong
  • 3
    13 hrs
    Correct
    Wrong
  • 4
    11 hrs
    Correct
    Wrong
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Answer : 2. "7 hrs"
Explanation :

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.

Q: The accounting software Tally was developed by 2737 0

  • 1
    Wipro
    Correct
    Wrong
  • 2
    TCS
    Correct
    Wrong
  • 3
    HCL
    Correct
    Wrong
  • 4
    Infosys
    Correct
    Wrong
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Answer : 2. "TCS"
Explanation :

Answer: B) TCS Explanation: Tally is one of the best business accounting software for accounting, inventory, payroll. It is economical and one of the most popular ERP software solutions available in the industry. Tally, an accounting software was developed by the multinational company TCS - Tata Consultancy Services.

Q: If (1 × 2 × 3 × 4 ........ × n) = n!, then 15! - 14! - 13! is equal to ___? 2725 0

  • 1
    14 × 13 × 13!
    Correct
    Wrong
  • 2
    15 × 14 × 14!
    Correct
    Wrong
  • 3
    14 × 12 × 12!
    Correct
    Wrong
  • 4
    15 × 13 × 13!
    Correct
    Wrong
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Answer : 4. "15 × 13 × 13!"
Explanation :

Answer: D) 15 × 13 × 13! Explanation: 15! - 14! - 13! = (15 × 14 × 13!) - (14 × 13!) - (13!) = 13! (15 × 14 - 14 - 1) = 13! (15 × 14 - 15) = 13! x 15 (14 - 1) = 15 × 13 × 13!

Q: The ages of Anushka, Kajal and Charu latha together are 57 years. Bharti is thrice as old as Anushka and Charu latha is 12 years older than Anushka. Then, the respective age of Anushka, Kajal and Charu latha is ? 2725 0

  • 1
    27, 9, 21
    Correct
    Wrong
  • 2
    9, 21, 27
    Correct
    Wrong
  • 3
    21, 27, 9
    Correct
    Wrong
  • 4
    9, 27, 21
    Correct
    Wrong
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Answer : 4. "9, 27, 21"
Explanation :

Answer: D) 9, 27, 21 Explanation: Let Anushka age = XCharu latha 12 yrs older than Anushka so Charu latha age = x+12Kajal is thrice as old as Anushka so Kajal age = 3xThe ages of Anushka, Kajal and Charu latha together are 57 yearsi.e x + (x+12) + 3x = 57=> 5x = 45:- x = 9Anushka age = 9Kajal age = 3x = 27Charu latha age = x+12 = 21

Q: कौन सा तत्व मैग्नीशियम की तरह सबसे अधिक व्यवहार करता है? 2724 0

  • 1
    सिलिकॉन
    Correct
    Wrong
  • 2
    स्ट्रोंटियम
    Correct
    Wrong
  • 3
    सल्फर
    Correct
    Wrong
  • 4
    टिन
    Correct
    Wrong
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Answer : 2. "स्ट्रोंटियम"
Explanation :

Answer: B) स्ट्रोंटियम व्याख्या: हम जानते हैं कि आवर्त सारणी के एक ही समूह के तत्वों में समान विशेषताएं होती हैं। यहाँ मैग्नीशियम और स्ट्रोंटियम ने कुछ समान गुण साझा किए क्योंकि वे दोनों एक ही समूह के हैं। Sr स्ट्रोंटियम का रासायनिक प्रतीक है जो एक समूह दो तत्व है; इसका परमाणु क्रमांक 38 है।

Q: A rectangular block has the dimensions 5x6x7 cm it is dropped into a cylindrical vessel of radius 6cm and height 10 cm. If the level of the fluid in the cylinder rises by 4 cm, What portion of the block is immersed in the fluid ? 2720 0

  • 1
    22/7 x 24/35
    Correct
    Wrong
  • 2
    22/7 x 36 x 4
    Correct
    Wrong
  • 3
    22/7 x 36/5
    Correct
    Wrong
  • 4
    22/7 x 37/21
    Correct
    Wrong
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Answer : 1. "22/7 x 24/35"
Explanation :

Answer: A) 22/7 x 24/35 Explanation: Since level of water increased in cylinder by height 4.  This is because of the rectangular block .   Therefore , area of rectangular block immersed in water is  = 227×6×6×4   Thats why portion of block immersed in water is  = (22/7 * 36 * 4) / total vol. of rectangle  = (22/7 * 36 * 4)/ (7*5*6)  = (22/7 * 24)/ 35.

Q: If 15 men 4 hours per day works for 14 days get Rs.35/- then how many men required if the work is 8 hours per day for 10 days they get 50/- ? 2719 0

  • 1
    12
    Correct
    Wrong
  • 2
    13
    Correct
    Wrong
  • 3
    14
    Correct
    Wrong
  • 4
    15
    Correct
    Wrong
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Answer : 4. "15"
Explanation :

Answer: D) 15 Explanation: We know M1×D1×H1W1 = M2×D2×H2W2    => 15×4×1435 = M×8×1050   => M = 15

Q: How many parallelograms will be formed if 7 parallel horizontal lines intersect 6 parallel vertical lines? 2718 0

  • 1
    215
    Correct
    Wrong
  • 2
    315
    Correct
    Wrong
  • 3
    415
    Correct
    Wrong
  • 4
    115
    Correct
    Wrong
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Answer : 2. "315"
Explanation :

Answer: B) 315 Explanation: Parallelograms are formed when any two pairs of parallel lines (where each pair is not parallel to the other pair) intersect.   Hence, the given problem can be considered as selecting pairs of lines from the given 2 sets of parallel lines.   Therefore, the total number of parallelograms formed = 7C2 x 6C2 = 315

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