Question

it tastes Kim 11 hours to proof a chapter of Hawkes Learning System introductory algebra book and it takes Bethany 6 hours how long would it take then working together

Answer 1

Kim alone = 11 hours

Bethany alone = 6 hours

Let time for Kim and Bethany = t

$\begin{gathered} \frac{1}{11}\text{ + }\frac{1}{6}\text{ = }\frac{1}{t} \\ \frac{6\text{ + 11}}{66}\text{ = }\frac{1}{t} \\ \frac{17}{66}\text{ = }\frac{1}{t} \\ \text{Cross multiply} \\ 17t\text{ = 66} \\ t\text{ = }\frac{66}{17} \\ t\text{ = 3}\frac{15}{17}\text{ hours} \end{gathered}$