Which number is a solution of the inequality 6 < h? a - -6 b - 5.9 c - 10 d - 0

Precalculus question, image attached.

Awater tank holds 18000 gallons. how long will it take for the water level to reach 6000 gallons if the water is used at anaverage rate of 450 gallons per day

In triangle △abc, ∠abc=90°, bh is an altitude. find the missing lengths. ah=4 and hc=1, find bh.