Problem solving find a rule

On an archaeological dig, Gabriel separates his dig site into sections with areas of 15 square feet each. There are 3 members digging in every section. What is the area of the dig site if 21 members are digging at one time? section 1 2 3 4 5 6 7 members 3 area1 15 Casey is making a design with triangles and beads for a costume. In his design, each pattern unit adds 3 triangles and 18 beads. Casey uses 72 triangles in his design. How many beads does Casey use? number of pattern units 1 2 3 4 ......... ? number of triangles 3 .......... number of beads 18 ..........