Keith sold half of his comic books and then bought nine more. He now has 20. How many did he begin with?

22 comic books.

Step-by-step explanation:

(20 - 9) * 2 First subtract 9 from 20

11 * 2 Multiply 11 by 2

22 is the product

0.16 or 16%

step-by-step explanation:

lets take a coin for example.

if you toss it twice, it has a 1/4 chance of landing on heads both times because 1/2 * 1/2 is 1/4.

with the cards, the chance of picking dog is 0.4. having two people pick one is like picking a card twice in a row. so 0.4 * 0.4 is 0.16, or 16%

the answer is ! ?