The answer is b, or 84ft squared. To find the area of a rectangle, you multiple the length by the width. So you multiply 10.5 by 8, which equals 84.
About 1 or if you are being exact 1.25 laps per minute
Pu 2 together straight up then one above it sideways
$2.56 * 15 gallons = $38.4 (total)
2 person split = $38.4 / 2 = $19.2/person
another friend = +1
$38.4 / 3 = $12.8
each person saves = $19.2 - $12.8 = $6.4/person
i hope this helps :)