Mark bought a book for $21.62. if he paid with two 20 bills what was his change

$18.38

Explanation:

Mark has two $20 bills.

Add 20 and 20, or multiply 20 by 2.

20+20=40, or 20•2=40.

This means that he started with $40 dollars in total.

Then, Mark spent $21.62 out of the $40 that he had.

Now all we have to do is subtract $40.00 and $21.62.

40.00 - 21.62 = 18.38.

Another way to get your answer is to take $21.62 and cancel out the first $20 bill out of that so you're left with $1.62.

Then you can subtract the second $20.00 that Mark had by $1.62.

20.00 - 1.62 = 18.38.

In conclusion, Mark is left with $18.38.

it would be that mali has the worst literacy rate than the others

nations must cooperate to bring about and maintain world peace.

nations must not wage wars or commit war crimes in a desire to control other nations.

i think i know which options you have but if these aren't options let me know