Question

Can someone please help me with question d?

Answer 1

       We already know that the hourly rate for John is : 1/6 and the hourly rate for Rick is : 1/8. What we don`t know is a hourly rate for Molly and we will call it 1 / x.
      The hourly rate for all together is: 1 / 3
      An equation is:
      1 / 3 = 1 / x + 1 / 6 + 1 / 8
      1 / 3 = 1 / x + 4 / 24 + 3 / 24
      1 / 3 = 1 / x + 7 / 24
      1 / x = 1 / 3 - 7 / 24
      1 / x = 8 / 24 - 7 / 24
      1 / x = 1 / 24
      1 / 3 = 1 / 24 + 1 / 6 + 1 / 8
      The hourly rate for Molly is 1 / 24. Molly can paint the room alone for 24 hours.