Question

The set {0,1} is closed under which operation?

none of the above
addition
multiplication
subtraction

Answer 1

A set has closure if you can do that operation in any direction and always get a number that belongs to that set.

Answer 2

A set is closed under an operation if you can take any 2 numbers in the set, perform the operation on them, and have the result be a number in the set


For example:

{1, 2, 3}

this set is NOT closed under addition because 2+3 = 5. The numbers 2 and 3 are in the set, but 5 is not.

Answer 3

lol nice

Answer 4

So for this one:
0+1 = 1
But also 0 * 1 = 0
So... it should be multiplication and addition, but thats not a choice. @jim_thompson5910 thoughts?

Answer 5

addition won't work because 1+1 = 2 is not in the set

Answer 6

same idea for subtraction

Answer 7

oh ok, sorry I didn't think that way. so its going to be multiplication

Answer 8

yes

0*0 = 0
0*1 = 0
1*0 = 0
1*1 = 1

a table is usually a good way to sort it all out