ANSWER
The multiplication, CA is defined, and its dimension is 3×2
EXPLANATION
Matrix A is a 2x3 matrix.
Matrix C is a 3×2 matrix.
The product of the two matrices , CA, is defined if and only if the inner product of their dimension are the same.

The inner products are the same.
Hence the matrix multiplication, CA is defined and its dimension is the outer products.

6
The upside down U means intersection
A intersect B intersect C is where all 3 circles overlap.
Sum up all the numbers to get 50
P (a intersect b intersect c) = 6/50 = 3/25
V(x) = (2x - 3)/(5x + 4)
The domain is all Real numbers except x = -4/5, because if x = -4/5 the denominator would be zero and you cannot divide by zero.
{x | x ∈ R, x ≠ -4/5}
w(x) = (5x + 4)/(2x - 3)
similarly, x ≠ 3/2
so, {x| x ∈ R, x ≠ 3/2}
The unit u have to use to measure the amount of water in a swimming pool is in Liters :)