Percentages are basically just fractions (1/100 s) of some total amount. i.e. 1 % of an amount is 1/100 of the total and 60 % is 60/100 of the total.
If you are given an amount and asked to calculate percentages of this amount, it is quite a simple process.
e.g. to find 15%, 60% and 150% of 250.
As illustrated above, to find a percentage of any given amount, we first divide that amount by 100, then multiply by the percentage we want to find.
As illustrated above, to express one number "a" as a percentage of another "b", we simply divide a by b then multiply by 100.