Hi All,

We're told that the sales tax on a $12.00 purchase is $0.66. We're asked for the sales tax on a $20.00 purchase. This question can be solved in a number of different ways (depending on how you want to organize your math). Here's how you can use a ratio to answer the question.

$20/$12 = 5/3.... so the ratio of the sales taxes will ALSO be 5/3...

5/3 = $X/$0.66
3X = $3.30
X = $1.10

Final Answer: B

GMAT assassins aren't born, they're made,
Rich

BTGmoderatorDC wrote:If the sales tax on a $12.00 purchase is $0.66, what is the sales tax on a $20.00 purchase?

A. $1.08
B. $1.10
C. $1.16
D. $1.18
E. $1.20

OA B

Source: Magoosh

We can also solve this question using equivalent ratios

We're comparing sales tax to retail price
We get: sales tax/retail price = $0.66/$12.00

What is the sales tax on a $20.00 purchase?
Let x = the sales tax

We can write: $0.66/$12.00 = x/$20.00
Cross multiply to get: (0.66)(20) = (12)(x)
To make things easier, let's first divide both sides by 4 to get: (0.66)(5) = (3)(x)
Then divide both sides by 3 to get: (0.22)(5) = x
Evaluate: 1.10 = x

Answer: B

Cheers,
Brent

BTGmoderatorDC wrote:If the sales tax on a $12.00 purchase is $0.66, what is the sales tax on a $20.00 purchase?

A. $1.08
B. $1.10
C. $1.16
D. $1.18
E. $1.20

If we let n = the sales tax on the 20 dollar purchase, we can create a proportion and solve for n:

0.66/12 = n/20

20 x 0.66 = 12n

13.2 = 12n

13.2/12 = n

1.1 = n

Thus, the sales tax is $1.10.

Alternate solution:

Since 0.66/12 = 0.055 = 5.5%, we see that the sales tax rate is 5.5%. Therefore, on a $20.00 purchase, the sales tax is 20 x 0.055 = $1.10.

Answer: B