Solving for the resultant couple
$C_R = \Sigma C$
$C_R = 40(16) - 30(12) + 60(8)$
$C_R = 760 \, \text{ lb}\cdot\text{in counterclockwise}$ answer
Solving for equivalent couple acting in the middle pulley
$12F = C_R$
$12F = 760$
$F = 63.3 \, \text{ lb}$
The resultant couple is composed of two 63.3 lb forces. answer