How to simplify 6 buses to 150people

For what values of b will f(x)= logbx be a decreasing function? (16 )

The tile along the edge of a triangular community pool needs to be replaced? ?

The party planning committee has to determine the number of tables needed for an upcoming event. if a square table can fit 8 people and a round table can fit 6 people, the equation 150 = 8x + 6y represents the number of each type of table needed for 150 people.