The correct option is A: $2.00
Explanation:
The question should be:
"The bill at the restaurant was $18.79 estimate the amount to leave as a 10% tip. A. $2.00 B. $3.00 C. $9.00 D. $21.00"
The general case is:
When we have a quantity A (where A is the 100%) the X% of A is:
(X%/100%)*A
In this problem, we have a bill of $18,79 and we want to leave a 10% tip.
Then $18,79 is the 100% we want to see how much is the 10% of $18,79
If we use the above equation we get:
Tip = (10%/100%)*$18,79 = $1,879
The option that approaches the best to this amount is option A, $2.00
Then the tip should be $2
The correct option is A.