Last year's sales = $320 million;
This year's sales = $385 million;
Increase = $65 million.

Now, 20% of $320 million is $64 million, which is very close to actual increase of $65 million.

Answer: C.

OR:
General formula for percent increase or decrease, or percent change:

\(Percent=\frac{Change}{Original}*100\) --> \(Percent=\frac{65}{320}*100=\frac{13}{64}*100\approx{\frac{13}{65}}*100=20%\).

Answer: C.
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65 is the closest multiple of 13: 5*13=65.
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Increase = 385 - 320 = 65

% Increase \(= \frac{65}{320} * 100 = 20%\)

Answer = C
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The problem is testing us on using the percent change formula:

(New Value – Old Value)/Old Value x 100

We are given:

February sales this year = 385 million

February sales last year = 320 million

We need to determine the percent increase between sales from last year to sales this year.

Thus, the new value = 385 million and the old value = 320 million. Let’s plug them into our percent change formula.

(New Value – Old Value)/Old Value x 100

[(385 – 320)/320] x 100

65/320 x 100

13/64 x 100 ≈ 13/65 x 100 ≈ 1/5 x 100 ≈ 20%.

The answer is C.
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Percentage increase = \(\frac{(Final - Original)}{Original}*100\)

\(\frac{(385 - 320)}{320}*100\)

\(\frac{(65)}{320}*100\)

\(\frac{(65)}{32}*10\) Cross off a zero from 320 and 100

\(\frac{65}{32}\) is close to 2, so 2 * 10 = 20%

Answer is C