In the equation, A is the answer, P is the percent, and W is the number.
In this case, P is 35%, or 0.35 in decimal form, and W is 20.
The mistake is that the person completing the problem multiplied W, the number, by 35 rather than by the decimal form of the percent. It should've been 0.35 times 20.
This would give the answer of 7, which is the correct answer for 35% of 20.
Answers:
7 is 35% of 20.
The error is that the number being multiplied by 20 should've been 0.35, not 35.