one week, kristi worked 3 days at a department store for 3 and a half hours each day. She was paid $9/h. How many hours did kristi work that week?

the height of the surface increases from the center out to the sides of the road.

step-by-step explanation:

as we move out we move away from the x-axis.

and as mentioned in the problem statement that height of a road increases when we move away from the center x.

hence proved that 3rd option

the height of the surface increases from the center out to the sides of the road.

is the correct option.