Proportions?

the cost C of steel tubing is jointly proportional to its length L, in feet, and the diameter D, in inches. If a 2 foot tube with a 6 inch diameter co

the cost C of steel tubing is jointly proportional to its length L, in feet, and the diameter D, in inches. If a 2 foot tube with a 6 inch diameter costs $84, find the cost of a 10 foot tube with a diameter of 12 inches.

or:the cost C of steel tubing is jointly proportional to its length L, in feet, and the diameter D, in inches. If a 2 foot tube with a 6 inch diameter costs $84, find the cost of a 10 foot tube with a diameter of 12 inches.

or:C = 7 * L * D $84 = 7 * 2ft * 6inAnd 10 = 2 * 5 ; 12 = 6 * 2 [2 * 5 = 10]So:$840 = 7 * 10ft * 12in

Tags:steel,tubing,mathematics,