Hey xsriel, Looks like your dad is correct again. taking one inch off every side of the paper actually equals taking off 2 inches because it actually cutting out of one side TWICE (check out my sketch in the attachment). So, initially it was 14 long by 8.5 wide. 2 inches off each side would leave, 12 inch long by 6.5 inch wide. then u calculate 14 times 8.5 = 119 then subtract 6.5 times 12 = 78 (which is what is left after the cutting) will give you

(119 - 78 = 41)

Hopefully i've been helpful

tsal15