Question

takes Kim 11 hours to proof a chapter of Hawkes Learning SystemsIntroductory Algebra book and it takes Bethany 6 hours. How long would it take them working together? (Round your answer to two decimal places)

Answer 1

3.88 hours

Step-by-step explanation:

If it takes Kim 11 hours to proof a chapter of Hawkes Learning Systems Introductory Algebra book, this shows that she will prove 1/11 of the chapter in 1 hour.

Similarly, if it took Bethany 6hrs to proof the same chapter, she will prove 1/6 of the chapter in 1hour

If x is the time take to read a chapter if the work together, the time it will take them working together is given as

`\begin{gathered} (1)/(x)=(1)/(11)+(1)/(6) \\ (1)/(x)=(6+11)/(66) \\ (1)/(x)=(17)/(66) \end{gathered}`

Cross multiply

`\begin{gathered} 17x=66*1 \\ 17x=66 \\ x=(66)/(17)=3(15)/(17)=3.88hours \end{gathered}`

Hence the time it will take them to work together is 3.88 hours