First let's get rid of the 
in the denominator of the fraction on the right side of the equation. This will help to get only 
and a coefficient on one side of the equation:
Now, simply divide by 730 to find :
C= .85p
Shipping 2 lbs is $1.80
C=.80p
So you already know the difference between the new number and original number, so all you have to do now is plug it in to this: Percentage Change=Difference/Original Number x100. So 17.99/257=.07x100 which equals 7%. So B is the correct answer.
When you add up the sum of the digits, it should be a multiple of three. 21 is 2 plus 1 equals 3, so since 3 is a multiple of three, 21 is divisible by 3
