Your proof is correct and very well done
9 cups of tea were sold.
For each 6 cups of coffee, 1 cup of tea was sold. So 54/6 = 9.
Answer:
5/24 or 20.8%
Step-by-step explanation:
Probability that the 7th grader is a boy = number of boys/(total kids) = 4/(4+4) = 1/2
Probability that the 8th grader is a boy = 5/(5+7) = 5/12
Probability that both are boys = 1/2*(5/12) = 5/24 or 20.8%