4 x 27 = 108 and 4 + 27 = 31... I don't think there is any pair of numbers that would equal -31. So the answer would be 4 and 27. Good luck! Hope this helped!!
we are given

where
F is the number of board feet
d is the diameter (in inches) of the log
Since, we have to minimize F
so, firstly we will find it's derivative


now, we can set it to 0
and then we can solve for d


so, we get diameter as
..............Answer
3 : 3 times 6 is 18, 2 times 9 is 18 and 3 times 3 is 9 plus 9 is 18
Area=pi x radius squared so (3.14)(10)squared = 314