Answer:
90%
Step-by-step explanation:
First, find the total number of tickets sold.
810 discount + 90 full-price = 900 tickets
Now you need to find what percent 810 is of 900.
% of 900 = 810
810/900 = 0.9
Convert this to a percentage.
0.9 × 100% = 90%
90% of tickets were sold at a discount.
