Answer:
10/36 or 5/18 or 27.777... %
Explanation:
In total there are 36 coupons and there is only 10 milkshake coupons using this you can make a fraction that represents 10 out of 36 which makes 10/36 you can also simplify this to make 5/18. To get the percentage you need to divide 10 with 36 using the fraction which makes about 27.7777... %