Her average speed was 12 miles per hour. Total distance over total time.
Add up all the numbers then divide how many ever digits there are
0 × <span>0 = 0
0 </span>× <span>1 = 0
1 </span>× <span>1 = 1
Which means multiplication is closed under {0, 1}
</span><span>1 </span>÷ <span>1 = 1
0 </span>÷ <span>1 = 0
</span>
Division is not closed under {0, 1}
1 + 1 = 2
Addition is not closed under {0, 1}
0 - 1 = -1
Subtraction is not closed under {0, 1} either
So it's only A. Multiplication which is closed under {0, 1}
