The manager of a store orders balance beams that cost $550 and sells them for $704. what percentage is the mark-up?

28%

Step-by-step explanation:

Percentage mark up = (new - original) / original  * 100 %

     new = 704

     original =  550                              

Substituting these values in

     Percentage mark up = (704 - 550) / 550  * 100 %

                                         =154/550 * 100%

                                         =.28*100%

                                            28%

After 4 hours, his body will have processed 28% because 7*4 = 28. But, you're trying to find what's left (so, subtract that % from 100)100%-28% = 72%Then multiply the percent left by the total number of milligrams of caffeine130*.72 = 93.6 mg