Answer :

[tex]36/45-->4/5 \\\boxed{80 \% }[/tex]
80%

Find the relevant fraction: 36/45

Reduce this by dividing top and bottom by 9, giving 4/5

Now multiply top and bottom by 20. This will make the denominator 100.

4/5 = 80/100

80/100 = 80%

So 36 is 80% of 45.