Answer
It will take a pulse 0.21 seconds to travel from one support to the other.
Work Step by Step
We can find the speed $v$ of the pulse as:
$v = \sqrt{\frac{F_T}{\mu}}$
$v = \sqrt{\frac{F_T}{m/L}}$
$v = \sqrt{\frac{120~N}{0.65~kg/8.0~m}}$
$v = 38.43~m/s$
We can find the time $t$ for a pulse to travel a distance of 8.0 meters as:
$t = \frac{L}{v}$
$t = \frac{8.0~m}{38.43~m/s}$
$t = 0.21~s$
It will take a pulse 0.21 seconds to travel from one support to the other.