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

      Two positive numbers differ by 2, and the sum of their

      reciprocals is 3/4. What is the larger number?
      A 4 Correct Answer Incorrect Answer
      B 3 Correct Answer Incorrect Answer
      C 5 Correct Answer Incorrect Answer
      D 6 Correct Answer Incorrect Answer

      Solution

      ATQ, Let the smaller number be x; then the larger is x + 2. Given: 1/x + 1/(x + 2) = 3/4 ( (x + 2) + x ) / [x(x + 2)] = 3/4 (2x + 2) / (x2 + 2x) = 3/4 4(2x + 2) = 3(x2 + 2x) 8x + 8 = 3x2 + 6x 3x2 βˆ’ 2x βˆ’ 8 = 0 Solve: Discriminant = (βˆ’2)2 + 4Β·3Β·8 = 4 + 96 = 100 x = [2 Β± 10] / (2Β·3) β‡’ x = 2, or x = βˆ’4/3 (reject negative). So smaller = 2, larger = 4.

      Practice Next
      ask-question