All members of our painting team paint at the same rate. If 20 members can paint a 1600 square foot wall in 30 minutes, then how long would it take for 15 members to paint a 1800 square foot wall, in minutes?

We know that the rate of the team is 1600 sq ft / 30 minutes, so the rate of each member is 1600 / (30 * 20) = 4/15 sq ft/minute. The time it takes 15 members to paint a 1800 square foot wall is 1800 / (4/15) = 225 minutes. So the answer is 225

one member takes 30 minutes to paint 1600/20 80 square feet so one does 8/3 sq feet in one minute so 15 members is 8/3 x 15 per minute=40 ft per minute 1800/40= 45 minutes