3 3/6 is equal to 21/6
1 2/3 is equal to 5/3
Both 3 and 6 go into 6 so the denominator is 6
Now multiply 5 by 2 because 3 goes into 6 twice.
10/6
You don't need to change 21/6 because the denominator is already 6
So now you need to add them
21/6+ 10/6= 31/6
Which is also 5 1/6
So the overall answer is 5 1/6