Jamal wants to store 30 computer files on floppy disks, each of which has a capacity of 1.44 megabytes (MB). Three of his files require 0.8 MB of memory each, 12 more require 0.7 MB each, and the remaining 15 require 0.4 MB each. No file can be split between floppy disks. What is the minimal number of floppy disks that will hold all the files?
<spanclass=′latex−bold′>(A)</span>12<spanclass=′latex−bold′>(B)</span>13<spanclass=′latex−bold′>(C)</span>14<spanclass=′latex−bold′>(D)</span>15<spanclass=′latex−bold′>(E)</span>16