πŸ“’ Too many exams? Don’t know which one suits you best? Book Your Free Expert πŸ‘‰ call Now!

  • google app store apple app store
  • βœ–

      Question

      The mean of five two-digit

      numbers is 34. Among these five numbers, two are 'P' and 'Q'. If the digits of both 'P' and 'Q' are swapped, the new mean of the five numbers changes to 14.2. Alternatively, if the other three numbers (excluding 'P' and 'Q') are multiplied by 'βˆ’1', the mean of the five numbers becomes 10. What is the sum of the tens digits of 'P' and 'Q'?
      A 8 Correct Answer Incorrect Answer
      B 10 Correct Answer Incorrect Answer
      C 20 Correct Answer Incorrect Answer
      D Can't be determined Correct Answer Incorrect Answer
      E None of these Correct Answer Incorrect Answer

      Solution

      ATQ,

      Let, P = 10a + b, Q = 10c + d & Sum of other 3 numbers = R Given P + Q + R = 34 Γ— 5 = 170 --- (1) P + Q – R = 10 Γ— 5 = 50 --- (2) Solving equation 1 & 2, we have, P + Q = (170 + 50)/2 = 110, So, R = 170 – 110 = 60 & (10a + b) + (10c + d) = 110 (b + d) = 110 – 10(a + c) --- (3) Again, given that, (10b + a) + (10d + c) + R = 5 Γ— 14.2 (10b + a) + (10d + c) + 60 = 71 (10b + a) + (10d + c) = 11 10(b + d) + (a + c) = 11 10[110 – 10(a + c)] + (a + c) = 11 1100 – 100(a + c) + (a + c) = 11 99(a + c) = 1089 (a + c) = 11 = Sum of tens digit

      Practice Next
      ask-question