Final answer:
To find the number of Joshua's friends who prefer volleyball and soccer over the other two sports, subtract the fractions that represent the preferences for basketball and baseball from 1.
Step-by-step explanation:
To find the number of Joshua's friends who prefer volleyball and soccer over the other two sports, we need to subtract the fractions that represent the preferences for basketball and baseball from 1 (since the total probability of preferences must equal 1).
Given that 1/5 of his friends like volleyball and 2/5 prefer soccer, we can calculate the fraction of his friends who prefer basketball and baseball.
Fraction of friends who prefer basketball = 1 - (1/5 + 2/5) = 1 - 3/5 = 2/5
Fraction of friends who prefer baseball = 1 - (1/5 + 2/5) = 1 - 3/5 = 2/5
Therefore, 2/5 of Joshua's friends prefer volleyball and soccer over the other two sports.