To re-phrase this: 50 is a certain percent of 90.
this can be written mathematically as 50=x%90
let's divide both sides by 10:
5=x%9
and divide both sides by 9:
\(\frac{5}{9} =x%\)
which in decimals is approximately 0.56 (but not exactly).
so 0.56=x%
and the x then 56
so 50 is approximately 56% of 90:
exactly 56%of 90 is 50.4