M14-34

Because that equation finds the percent the box size decreased. The box size decreased by 20%; however, the question is asking you how much the price decreased based on the decrease in box size.

You want to first find the cost of the juice per cubic centimeter. Lets say P = the price of the total box

Old price per cubic centimeter: (P/1000)
New price per cubic centimeter: (p/1200)

Now find the percent decrease: (OLD - NEW)/(OLD) => ((P/1000) - (P/1200)) / (P/1000) = 1/6 = .1667 => 16.67 percent (answer choice B)

there is a 20% increase in the size which needs to be compensated with the decrease in price.
now 20% increase equals 16.666% decrease. Hence the answer

List of interchangeable percentage(%)

One can use the below table to change percentage.
Example if A to B we have X% Increase.
What will (let Y) be the percentage decrease from B to A.

This can be easily calculated if X= 25% then Y = 20%
Refer below table for some known handy conversions.

........ % Increase ... % Decrease
........ =========== =============
100/11 = 9.09 ........ 8.33 ........ X/12
100/10 = 10 ........... 9.09 ........ X/11
100/9 = 11.11 ........ 10 ........ X/10
100/8 = 12.5 ......... 11.11 ........ X/9
100/7 = 14.28 ........ 12.5 ........ X/8
100/6 = 16.66 ........ 14.28 ........ X/7
100/5 = 20 ........... 16.66 ........ X/6
100/4 = 25 ........... 20 ........ X/5
100/3 = 33.33 ........ 25 ........ X/4
100/2 = 50 ............ 33.33 ........ X/3
100/1 = 100 ............ 50 ........ X/2

I have edited the question and the solution by adding more details to enhance its clarity. I hope it is now easier to understand.

The respective columes are 1000 and 1200.
Take the price to be 1200.
this gives price per unit
initial = 1.2
New= 1
change = 0.2
now 0.2/1.2 = 1/6 =16.67%