Final answer:
To find the percentage of single-shot espressos sold, divide the number of single-shot espressos by the total number of espressos sold and multiply by 100. In this case, 40% of the espressos sold were single-shot.
Step-by-step explanation:
To find the percentage of single-shot espressos sold, we need to divide the number of single-shot espressos by the total number of espressos sold and then multiply by 100. There were 22 single-shot espressos sold and 33 double-shot espressos sold, so the total number of espressos sold is 22 + 33 = 55. The percentage of single-shot espressos sold is (22/55) * 100 = 40%.