7th grade math 15 question

Pyramid shown has a square base that is 18 inches on each side has a surface area of 164 square inches what is the slant height

Atrain leaves little? rock, arkansas, and travels north at 90 kilometers per hour. another train leaves at the same time and travels south at 80 kilometers per hour. how long will it take before they are 680 kilometers? apart?

Consider the sequence below. 3 , 1 , 1/3 , 1/9 , select the explicit function which defines the sequence.