Answer
$\eta_{pump-motor}=\frac{W_{fluid}}{W_{electric}}$
It can not be greater
Work Step by Step
The pump efficiency:
$\eta_{pump}=\frac{W_{fluid}}{W_{mecanic}}$
The motor efficiency:
$\eta_{motor}=\frac{W_{mecanic}}{W_{electric}}$
Then the pump-motor efficiency is:
$\eta_{pump-motor}=\eta_{pump}*\eta_{motor}=\frac{W_{fluid}}{W_{electric}}$
The combined pump-motor efficiency can not be greater than either the pump or the motor efficiency because both efficiencies are less than 1.
