Key is to Lock as Password is to ?

B. ACCESS

If A + B = C, B - A = D, and D * 2 = E, what is the value of E if A = 3 and B = 7?

B. 10

If X * Y = Z, Y / X = W, and W + 5 = V, what is the value of V if X = 2 and Y = 10?

C. 15

If P - Q = R, Q + R = S, and S / 2 = T, what is the value of T if P = 15 and Q = 5?

B. 12.5

If M + N = O, N * 2 = P, and P - O = Q, what is the value of Q if M = 4 and N = 6?

A. -2