It takes him 2 minutes to complete a math problem. The number of minutes he will use for 550 math problems can be computed below
[tex]\begin{gathered} \text{1 math problem = 2 minutes} \\ 550\text{ math problem = 550}\times2=1100\text{ minutes} \\ 60\text{ minutes = 1 hour} \\ 1100\text{ minutes = }\frac{1100}{60}=18.33\text{ hours} \end{gathered}[/tex]
It will take him 18.33 hours to do 550 math problems(He could use a little less or more than 18.33 hours because some problems might take less or more than the calculated 2 minutes per math problem).
