How to solve markup and discounts percent

You multiply the percent by 100 which should make it a decimal, for example,

20% • 56 = x

First you have to make 20% (example) a decimal, the rule is that you must multiply the percent always by 100 not 10 but 100
20% to a decimal is 0.2
Since you know what 20% is as a decimal,
You now can multiply 56 (example) and 0.2 (example) which brings you to

That should answer your question

4hours and 40 mins she would be 120 meters high