Blimey,pilots unable to even count correctly ! VERY scary !
Start a course on Jan 1st 2009 & end on Dec 31 2013.......How many years ? C'mon you children of the magenta line, think outside of the box & delve into the problem. This question included in next year's selection test !
Actually, recent visit to the Souk, I bought some stuff & the guy placed the items on one side of a weighing scale . On the other side, he placed various rocks of various sizes and , obviously, various weights until all was balanced. Pencil & paper calculation resulted in a negotionable price being offered. Magic. Bring back the old days !