CAT Practice Question and Answer

Q: A letter is takenout at random from 'ASSISTANT'  and another is taken out from 'STATISTICS'. The probability that they are the same letter is : 1545 0

  • 1
    35/96
    Correct
    Wrong
  • 2
    19/90
    Correct
    Wrong
  • 3
    19/96
    Correct
    Wrong
  • 4
    None of these
    Correct
    Wrong
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Answer : 2. "19/90"
Explanation :

Answer: B) 19/90 Explanation: ASSISTANT→AAINSSSTT STATISTICS→ACIISSSTTT Here N and C are not common and same letters can be A, I, S, T. Therefore  Probability of choosing A =  2C19C1×1C110C1 = 1/45   Probability of choosing I = 19C1×2C110C1 = 1/45 Probability of choosing S = 3C19C1×3C110C1 = 1/10 Probability of choosing T = 2C19C1×3C110C1 = 1/15 Hence, Required probability =   145+145+110+115= 1990

Q: What is the number of digits in 333? Given that log3 = 0.47712? 5483 0

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

Answer: B) 13 Explanation:  Let   Let x=333 = 333    Then, logx = 33 log3     = 27 x 0.47712 = 12.88224    Since the characteristic in the resultant value of log x is 12   ∴The number of digits in x is (12 + 1) = 13    Hence the required number of digits in 333is 13.

Q: Find value of log27 +log 8 +log1000log 120 1670 1

  • 1
    1/2
    Correct
    Wrong
  • 2
    3/2
    Correct
    Wrong
  • 3
    2
    Correct
    Wrong
  • 4
    2/3
    Correct
    Wrong
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Answer : 2. "3/2"
Explanation :

Answer: B) 3/2 Explanation:  = log 33 + log 23+ log 103log10×3×22        =log33 12+log 23+log 10312log(10×3×22)                 =12log 33+3 log 2+12 log103log10+log3+log22                 =32log 3 + 2 log 2 + log 10log 3 + 2 log 2 + log 10 = 32

Q: The Value of  logtan10+logtan20+⋯⋯+logtan890 is 1425 1

  • 1
    -1
    Correct
    Wrong
  • 2
    0
    Correct
    Wrong
  • 3
    1/2
    Correct
    Wrong
  • 4
    1
    Correct
    Wrong
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Answer : 2. "0"
Explanation :

Answer: B) 0 Explanation: = log tan10+log tan890 + log tan20+ log tan880+⋯⋯+log tan450     = log [tan10 × tan890] + log [tan20 × tan880 ] +⋯⋯+log1     ∵ tan(90-θ)=cotθ and tan 450=1     = log 1 + log 1 +.....+log 1    = 0.

Q: For x∈N, x>1,  and  p=logxx+1, q=logx+1x+2 then which one of the following is correct? 6898 2

  • 1
    p < q
    Correct
    Wrong
  • 2
    p = q
    Correct
    Wrong
  • 3
    p > q
    Correct
    Wrong
  • 4
    can't be determined
    Correct
    Wrong
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Answer : 3. "p > q"
Explanation :

Answer: C) p > q Explanation: kl>k+1l+1 for (k,l) > 0 and  k > l        Let     k = x+1    and   l = x       Therefore, x+1x>(x+1)+1(x)+1        (x + 1) > x       Therefore, log(x+1)log(x)>log(x+2)log(x+1)       ⇒logxx+1 >logx+1x+2

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Answer :
Explanation :

Let the speed of Kaushik be Sk and speed of Piyush be Sp and let the time taken by Piyush be t second then,  SkSp = 800t+20600t = 23since given ratio   t = 20 s   Speed of Piyush = Sp = 600/20 = 30 m/s   and    Speed of Kaushik = 800/40 = 20 m/s

Q: A and B runs around a circular track. A beats B by one round or 10 minutes. In this race, they had completed 4 rounds. If the race was only of one round, find the A's time over the course: 4090 0

  • 1
    8 min
    Correct
    Wrong
  • 2
    7.5 min
    Correct
    Wrong
  • 3
    12.5 min
    Correct
    Wrong
  • 4
    12 min
    Correct
    Wrong
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Answer : 2. "7.5 min"
Explanation :

Answer: B) 7.5 min Explanation: B runs around the track in 10 min.  i.e ,    Speed of B = 10 min per round  Therefore,  A beats B by 1 round   Time taken  by A to complete 4 rounds    = Time taken by B to complete 3 rounds    = 30 min    Therefore, A's speed = 30/4 min per round = 7.5 min per round  Hence, if the race is only of one round A's time over the course = 7 min 30 sec

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Answer : 2. "8"
Explanation :

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)

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