๐Ÿ“ข Too many exams? Donโ€™t know which one suits you best? Book Your Free Expert ๐Ÿ‘‰ call Now!

  • google app store apple app store
  • โœ–

      Question

      โ€˜Aโ€™ and โ€˜Bโ€™ alone can do a certain work in 30

      days and 40 days, respectively. Both started the work together but after โ€˜xโ€™ days โ€˜Aโ€™ left the work and the rest work was completed by B alone in โ€˜2xโ€™ days. Find the total time taken to complete the whole work in this way.
      A 28days Correct Answer Incorrect Answer
      B 12days Correct Answer Incorrect Answer
      C 27.69days Correct Answer Incorrect Answer
      D 48days Correct Answer Incorrect Answer

      Solution

      Total work = 120 units (LCM of 30 and 40) Efficiency of โ€˜Aโ€™ = 120/30 = 4 units/day Efficiency of โ€˜Bโ€™ = 120/40 = 3 units/day According to the question, โ€˜Aโ€™ worked for โ€˜xโ€™ days and โ€˜Bโ€™ worked for โ€˜2x days. Therefore, (4+3)x + 3 ร— 2x = 120 Or 7x + 6x = 120 Or x = 120/13 total time taken to complete the whole work = 3ร—120/13 =360/13 days =27.69days

      Practice Next
      ask-question