You will get an extra 2 1/2 inch strip out of a FQ. Because 2 1/2 times 3 is 7 1/2 and you will end up with 1 1/2 inch strip left over and you then have to allow for squaring.
2 1/2 times times 7 is 17 1/2. So allowing for squaring you can get an extra strip.
In that case I would use FQ.