Out of the given options, the mineral phase affects the speed of a seismic wave.
<u>Explanation:</u>
The speed of a seismic wave is governed by three interrelated factors, viz. the composition of the rock, pressure, and temperature.
Seismic waves travel at different speeds in different mediums.
This property of the seismic waves tends it to change the speed where the concentration of minerals in the rocks varies.
Other than that, the increasing temperature beneath the Earth's surface decreases the speed of the seismic waves, and the speed increases with increasing pressure as the waves go penetrating deep down into the Earth's interiors.
$540, you just multiply $50 x those 6 months =$300 then you multiply $40 x those other 6 months and u get $240 and then you add the 240 and the 300 and get 540
