Question

4. Betty Kusack and Theresa Peña together can do a job in 20 hours. Working alone,Betty can do the job in 60 hours. How long would it take Theresa, working alone, todo the job?AnswerH

Answer 1

Given:

Betty and Theresa together complete a job in 20 hours.

Betty alone does a work in 60 hours.

The aim is to find the time Theresa will take to complete the job alone.

Therefore,

Betty and Theresa's 1 day work:

`=(1)/(20)`

Betty's 1 day work when he works alone:

`=(1)/(60)`

Now, Theresa's 1 day work when he works alone is given by:

`\begin{gathered} =(1)/(20)-(1)/(60) \\ =(3-1)/(60) \\ =(2)/(60) \\ =(1)/(30) \end{gathered}`

Hence, Theresa can do the job in 30 hours working alone.