Answer:
1. Able must pay Regal Corporation $599,400 on September 1, 2019, when the note matures.
2. The amount of Interest Able will recognize on this Notes Payable is	39,600
3. The total cash (including interest) paid for the building purchased by Able is $1,179,400
4. Payroll related expense does not come into picture in this question. So it is not answered.
Explanation:
1. According to the given data we have the following:
Rate of Interest = 11%
Therefore:      
Year                      Amount	Interest      
September 1, 2018       $540,000      
December 31, 2018            $19,800      
September 1, 2019                     $39,600      
Total                      $540,000     $59,400
Therefore, Total Payable=Notes payable+Interest	540000      Total Payable= $540,000+$59,400
Total Payable=$599,400
Able must pay Regal Corporation $599,400 on September 1, 2019, when the note matures.
2. The amount of Interest Able will recognize on this Notes Payable is	39,600
3. To calculate The total cash paid for building purchased by Able including interest we have to make the following calculation:
Total cash paid for purchase of building=Cash paid at the time of purchase of building+Notes payable+Interest	
Total cash paid for purchase of building=$580,000+$540,000+$59,400
Total cash paid for purchase of building=$1,179,400
The total cash (including interest) paid for the building purchased by Able is $1,179,400
4. Payroll related expense does not come into picture in this question. So it is not answered.