It depends on what location the sun is setting. For example, in the east side of the North America, the sun may set near 7pm to 7:30pm now that we are in summer, but in Europe, the sum may set at 8pm
13 and 2, I think that is the only one left.
The associative property allows you to change the <em>grouping</em> of addends or factors without changing the value of the expression.
