When 28 is divided by the positive integer a, the remainder is 1. What is the sum of all the possible values of a for which this is true? Choose one.
A) 2  B) 3  C) 9  D) 30  E) 39
The only possible values of the form 28=ap+1 are 3,9 or 27   The sum = 3+9+27= 
<gadget id="calculator">3+9+27</gadget>
<output>39</output>
39. E is the correct answer. We dont need to look for values &gt;28 as all these values will leave a remainder of 28 and not 1.
<result>E</result>
When 28 is divided by the positive integer a, the remainder is 1. What is the sum of all the possible values of a for which this is true?