Question

Mary has 27 tests to correct. It takes her 1/9 of an hour to correct each test. How many hours will it take Mary to correct all the tests?

Answer 1

To find the total time that Mary will spend correcting the tests,we have to multiply 27 by 1/9 using the general rule for the product of fractions:

`(a)/(b)\cdot(c)/(d)=(a\cdot c)/(b\cdot d)`

then, in this case we have the following:

`\begin{gathered} 27=(27)/(1) \\ \Rightarrow27\cdot(1)/(9)=(27)/(1)\cdot(1)/(9)=(27)/(9)=3 \end{gathered}`

therefore, Mary will spend 3 hours correcting the 27 tests