The given equation is,

Thus, option (C) is the correct solution.
Take a look at the attachment to see the solution.
A = future value
P = principal (P = 12,000)
r = interest rate (r=6)
n = time periods (n=12)
3*|2-7| = 3*|-5|......absolute values are positive even when they say negative.
so 3*| -5 | = 3 * 5 = 15
If 1/3 = 12, then multiply 12 by 3 to get the number, which is 36
then split 36 in half, and you get 18.
hope this helps!
To answer 13 you have to convert the numbers there are 8 pints in a gallon so 64/8=8 so there are 8 gallons
For 14 you would do 64x9=576 and there are 12in in a foot so 576/12 so 48 ft and there are 3 feet in a yard so 48/3=16 so Devon need 16 yds of ribbon