Answer is 3/20 of a pizza per person
Step by step
We will divide 9/10 of a pizza by 6 (Garland + 5 friends)
9/10 divided by 6
Flip the 6 and multiply across
9/10 x 1/6 = 9/60
Simplify by dividing top and bottom by 3 = 3/20 of a pizza
Check your work
9/10 is .9 as a decimal, you can divide .9 by 6 = .15 or 15/100 of the pizza, the same as 3/20.