If you started with 5 boxes at the first figure and you add 3 each time and the second figure is 8 and you keep adding 3 how many boxes will you have at the 65th figure?
I don't see any "figure", but it sounds like arithmetic progression:
nth term = F + (N -1) x D
65th term =5 + (65 - 1) x 3 =197
Thanks
+11 
