Question

Shane can shovel the driveway in 4 hours, but if his sister helps it would take 2 hours. How long would it take Taylor to shovel the driveway alone

Answer 1

Answer:  4 hours

Step-by-step explanation:

Shane: $\dfrac{1}{4}\ \text{job per hour}$

Taylor: $\dfrac{1}{x}\ \text{job per hour}$

Together: $\dfrac{1}{2}\ \text{job per hour}$

Shane + Taylor = Together

    $\dfrac{1}{4}$      +     $\dfrac{1}{x}$      =       $\dfrac{1}{2}$

  $(8x)\dfrac{1}{4}$    +   $(8x)\dfrac{1}{x}$    =     $(8x)\dfrac{1}{2}$

   2x    +      8    =       4x

                    8   =        2x

                    4   =          x