So,
Matt answered 20 out of 25 questions.
[tex] \frac{20}{25} [/tex]
We need to get the denominator to be 100. We can do that by multiplying the fraction by a form of 1.
[tex] \frac{20}{25} * \frac{4}{4} = \frac{80}{100} [/tex]
From here, it should be easy to see that Matt has answered 80% of his test.
