Final answer:
The probability that a first year student requires both a developmental math course and a developmental English course is -0.23 or 23%.
Step-by-step explanation:
To find the probability that a first-year student requires both a developmental math course and a developmental English course, we can use the formula:
P(A and B) = P(A) + P(B) - P(A or B)
Given that the probability of needing neither course is 0.70, the probability of needing a developmental math course is 0.22, and the probability of needing a developmental English course is 0.25, we can substitute these values into the formula:
P(Developmental Math and English) = P(Developmental Math) + P(Developmental English) - P(Neither)
P(Developmental Math and English) = 0.22 + 0.25 - 0.70
P(Developmental Math and English) = 0.47 - 0.70
P(Developmental Math and English) = -0.23
Therefore, the probability that a first-year student requires both a developmental math course and a developmental English course is -0.23 or 23%.