The way I figured this one out was saying that if it takes 2lbs to stretch it to 12 inches and 5lbs to stretch to 18 inches that means that 3 additional pounds = 6 inches. Therefore, each additional pound is 2 inches. We know already that with 2 lbs it was 12 inches in length and we can also say that 2 lbs = 4 inches. So subtract 4 from 12 and you end up with the answer of 8 inches.
See attached image for work.
Known :
w = 12 feet
h = 18 feet
V = 3.240 feet³
Asked :
l = ...?
Answer :
V = l × w × h
3240 = l × 12 × 18
3240 = 216 l
l = 3240 ÷ 216
l = <u>1</u><u>5</u><u> </u><u>feet</u>
So, the length is 15 feet
<em>Hope it helps and is useful</em><em> </em><em>:</em><em>)</em>
29.6+73+33=135.6 180-135.6=44.4
So, 350 out of 1750
350/1750=
.1828/1
percent is parts out of 100 so x%=x/100
make bottom number 100
0.1828/1 times 100/100 =18.28/100=18.28%
about 18% saved