In positional number systems, the number zero is important

Question 11 options:

1)	for multiplication.
2)	as a placeholder.
3)	for counting.
4)	for addition.

How would someone who has memorized the value of 2¹⁰ compute the value of 2¹²?

Question 12 options:

1)	Double the value of 210 and then double it again.
2)	Multiply the value of 210 by 12.
3)	Multiply the value of 210 by 2.
4)	Add 12 to the value of 210.

The smallest hexadecimal digit is

Question 13 options:

1)	0
2)	1
3)	A
4)	F