15 x 7% = 105%
Obviously that's not how those numbers work, but you get the idea: it's not necessary to filter all the air at once.
Obviously that's not how those numbers work, but you get the idea: it's not necessary to filter all the air at once.
2. The article says "15x more", so the right math would be 100x16/17=94.12 .
Fan X moves "15x more" air than fan Y. For every 1 unit of air fan X moves, Y will move 1x15 = 15 units. In the time it takes fan Y to move 100 units of air, fan X will move 100*(1/15) units, or 6 2/3rds units. 6.666... rounds to 7.