Question

Chris took 3 4/5 hours to clean the bathroom. He took 2 1/2 hours to clean the kitchen. How much longer did it take Chris to clean the bathroom ?Write your answer as a mixed number in simplest form.

Answer 1

As we are comparing the time it took Chris to clean the bathroom and the kitchen, we need to subtract the time that Chris took to clean the kitchen from the time he took to clean the bathroom, as shown below.

`3(4)/(5)_{}-2(1)/(2)=(15+4)/(5)-(4+1)/(2)=(19)/(5)-(5)/(2)`

Then,

`\begin{gathered} \Rightarrow3(4)/(5)_{}-2(1)/(2)=(2\cdot19-5\cdot5)/(5\cdot2)=(38-25)/(10)=(13)/(10) \\ \Rightarrow3(4)/(5)_{}-2(1)/(2)=(10)/(10)+(3)/(10)=1+(3)/(10)=1(3)/(10) \\ \Rightarrow3(4)/(5)_{}-2(1)/(2)=1(3)/(10) \end{gathered}`

The answer is 1 3/10 hours