I recently took a test and I failed to understand how the answered was
derived.. Heres the question:

A malfunctioning transmitter designed to transmit at 28 watts of power
has a power output of 7 watts. In its current state, its signal is
being received by a base station at 5uV. If the transmitter were to be
repaired and had its proper output of 28 watts, what would the receive
signal signal at the base station be?

I figured if the transmitter were repaired, that would be a improvement
of 6dB on the transmit side. At the receiver I would figure the signal
should be 20uV, but somehow the the correct answer was a receive signal
of 10uV. I have no idea how they derived 10 uV and no explaination was
given. Can someone help me out with the math here?