a. We start by noting the number of hours Mark worked, given that h is the number of hours Chris worked.
To get this, we look for the relationship between the number of hours Mark worked and the number of hours Chris worked
From the question, we are told that they worked the same umber of hours, so the number of hours Mark worked is also h hours since they worked equal number of hours.
b. We shll now use the relationship with Kari for both Chris annd Mark to write two equations.
For Chris, we rae told that Kari worked twicw as many hours as he worked.
So if Chris worked h hoirs, then Kari worked 2 * h = 2h hours
For Mark, we are told that Kari worked 10 less than 3 times the number of hours Mark worked
The number of hours Mark worked was h hours, 3 times this is 3 * h = 3h
10 less than this would be (3h - 10) hours
c. An equation describing the expression above;
Since each expressin represents the number o hours Kari worked, then the two expressions must be equal.
Thus;
2h = 3h - 10