please help with homework

What is the "critical F" for the following test criteria? a. a = .05, three samples, n = 10 in each sample b. a = .05, four samples, n = 10 in each sample c. a = .01, three samples, n = 11 in each sample d. a = .05, three samples, n1 = 6, n2 = 8, n3 = 10 e. a = .05, two samples, n1 = 9, n2 = 12