All of the members of our spray-painting team paint at the same speed. If 12 team members can paint a 2400 square foot wall in 45 minutes, then how many minutes would it take for 9 team members to paint a 3600 square foot wall?
2400 sq ft / 45 minutes/12 members = 4.44 sq ft / min/member (each member can paint 4.44 sqft/min)
3600 sq ft / ( 4.44 sqft/min/mem * 9 members) = 90 mins