How many four digit numbers have no repeat digits, do not contain zero, and have a sum of digits H equal to 28?
Choose the most appropriate option.
A) 14	B) 24	C) 28	D) 48	E) 96
First, look for all 4 digits without repeat that add up to 28. To avoid repetition, start with the highest numbers first.   Start from the largest number possible 9874.   Then the next largest number possible is 9865.   After this, you'll realize no other solution. Clearly the solution needs to start with a 9 (cuz otherwise 8765 is the largest possible, but only equals 26). With a 9, you also need an 8 (cuz otherwise 9765 is the largest possible, but only equals 27). With 98__ only 74 and 65 work.   So you have two solutions. Each can be rearranged in 4!=24 ways. So H=24+24=48.48
<result>D</result>
How many four digit numbers have no repeat digits, do not contain zero, and have a sum of digits H equal to 28?