If the printer print 27 pages in 4.5 minutes then we need to find the number of minutes it takes to print one page.
4.5/27 = 0.167
Now to find the time it takes to print 324 pages just multiply 0.167 by 324.
324 * 0.167 = 54
So it takes 54 minutes for the printer to print 324 pages.
Hope this helps :)