It will take him 16 hours. Hope it helps
First convert all your measurents into inches 600in, 480in,18in then multiply them to get 5184000 cubic inches, convert cubic inches to gallons and you have 22441US gal lqd divide 22441 by 1000 and it will take you 22.441 hours
From the table,
y - 72 = (64 - 72)/(24 - 12) (x - 12) = -8/12(x - 12) = -2/3(x - 12)
y - 72 = -2/3(x - 12)
y - 64 = (56 - 64)/(36 - 24) (x - 24) = -8/12 (x - 24) = -2/3(x - 24)
y - 64 = -2/3(x - 24)
y - 56 = (64 - 56)/(24 - 36) (x - 36) = 8/-12 (x - 36) = -2/3(x - 36)
y - 56 = -2/3(x - 36)
Divide both 63 and 98 by 7, which gives you 9/14