a.eight tiles cost 20$, and 10 tiles cost 25$
b.eight tiles cost 20$, and 20 tiles cost 16$
c.four men moved 2,000 boxes in 6 hours,and 8 men moved 2,000 boxes in 3 hours.
d.four men moved 2,000 boxes in 6 hours, and 8 men moved 2,000 boxes in 12 hours.