For the declarations:

    REAL, DIMENSION(100, 100) :: A, B, C
    REAL, DIMENSION(100, 500) :: P, Q, R
    REAL, DIMENSION(500, 100) :: T

8.1 What is the difference between C = MATMUL(A,B) and C = A*B?

Answer: the former is a matrix multiply and the latter multiplies
each element separately.