Answer: 20%
Step-by-step explanation:
The "given the customer ordered a cold drink" means we only focus on the bottom row of values. There are B = 8+12+5 = 25 people who ordered a cold drink. Of that total, A = 5 people ordered a cold large drink.
The probability we want is A/B = 5/25 = 1/5 = 0.20 = 20%