Since each plate has 1 and 5/6 brownies on it and Janessa has 4 plates, you would need to multiply 1 and 5/6 by 4. This is equivalent to adding 1 and 5/6 a total of 4 times:
Note that 1 and 5/6 written as an improper fraction is11/6.
11/6 * 4 = 44/6 or 22/3
22/3 is equal to 7 and 1/3
Janessa has a total of 7 1/3 brownies