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  • Question
  • In an examination paper of five questions 5% of the candidates answered all of them and 5% answered none. Of the rest 25% candidates answered only one question and 20% answered 4 question. If 396 candidates answered either 2 question or 3 question. The number of candidates that appeared for the examination was


  • Options
  • A. 800
  • B. 1000
  • C. 850
  • D. 900

  • Correct Answer
  • 800 

    Explanation

    Let total number of candidates in Exam = a
    Number of candidates answered 5 questions = a x 5% = a x 5/100 = 5a/100 = a/20
    Number of candidates answered not any questions = a x 5% = a x 5/100 = 5a/100 = a/20
    ? Remaining students = a - ( a/20 + a/20) = a - ( 2a/20 ) = a - ( a/10 ) = (10a - a)/10 = 9a/10
    Number of candidates answered only 1 question = ( 9a/10 ) x 25% = ( 9a/10 ) x 25/100 = 9a/40
    Number of candidates answered 4 questions = ( 9a/10 ) x 20% = ( 9a/10 ) x 20/100 = 9a/50
    Given number of candidates awarded either 2 questions or 3 questions = 396
    ? a - ( a/20+ a/20 + 9a/40 + 9a/50 ) = 396
    ? a - ( a/10 + 9a/40 + 9a/50 ) = 396
    ? a - ( ( a x 20 + 9a x 5 + 9a x 4 )/200) = 396
    ? a - ( ( 20a + 45a + 36a )/200) = 396
    ? a - ( 101a/200) = 396
    ? ( 200a - 101a)/200 = 396
    ? ( 99a)/200 = 396
    ? a = 396 x 200/99
    ? a = 4 x 200 = 800
    ? a = 800
    Hence, number of candidates = 800


  • More questions

    • 1. 
      The product of two consecutive odd numbers is 19043. Which is the smaller one?

    • Options
    • A. 137
    • B. 131
    • C. 133
    • D. 129
    • Discuss
    • 2. 
      The angle of elevation of the top of a hill from each of the vertices A, B, C of a horizontal triangle is ?. The height of the hill is :

    • Options
    • A. b tan ? cosec B
    • B. a tan ? cosec A 2
    • C. c tan ? cosec C 2
    • D. None of these
    • Discuss
    • 3. 
      From a point on a circular tract 5 Km long A, B and C started running in the same direction at the same time with speeds of 2 1? 2 Km/h, 3 Km/h and 2 Km/h. respectively. Then on the starting point all three will meet again after :

    • Options
    • A. 30 hours
    • B. 6 hours
    • C. 10 hours
    • D. 15 hours
    • Discuss
    • 4. 
      The radius of the wheel of a vehicle is 70 cm. The wheel makes 10 revolutions in 5 seconds. The speed of the vehicle is?

    • Options
    • A. 29.46 km/hr.
    • B. 31.68 km/hr.
    • C. 36.25 km/hr.
    • D. 32.72 km/hr.
    • Discuss
    • 5. 
      A library has two books each having three copies and three other books each having two copies. In how many ways can all these books be arranged in a shelf so that copies of the same book are not separated?

    • Options
    • A. 120
    • B. 180
    • C. 160
    • D. 140
    • Discuss
    • 6. 
      Find the LCM of 1/3, 2/9, 5/6 and 4/27.

    • Options
    • A. 1/54
    • B. 10/27
    • C. 20/3
    • D. 3/20
    • Discuss
    • 7. 
      A runs 1 3? 8 times as fast as B. If A gives B a start of 120 m and they reach the goal at the same time, the goal is at a distance of:

    • Options
    • A. 360 m
    • B. 440 m
    • C. 460 m
    • D. 380 m
    • Discuss
    • 8. 
      124.35 % 8096 =?

    • Options
    • A. 2000
    • B. 10000
    • C. 1000
    • D. 12000
    • Discuss
    • 9. 
      Given that log 10 2 = 0.3010 the value of log 10 5 is?

    • Options
    • A. 0.3241
    • B. 0.6911
    • C. 0.6990
    • D. 0.7525
    • Discuss
    • 10. 
      In a month of 31 days, third Thursday falls on 16th. What will be the last day of the month?

    • Options
    • A. 5th Friday
    • B. 4th Saterday
    • C. 5th Wednesday
    • D. 5th Thirsday
    • Discuss


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