What is the sum of all 3 digit positive integers that can be formed using the digits 1, 5, and 8, if the digits are allowed to repeat within a number?  Select the correct option:	A) 126	B) 1386	C) 3108	D) 308	E) 13986
There can be 27 numbers. Every digit has three possibilities because question permits repetition. So it becomes a very good summation problem.   If there are 27 digits. There are 27 hundred digits, 27 tens digit and 27 ones digit to be summed. Of 27 hundred digits, 9 of them are 1, 9 of them are 5 and the last 9 are 8. Same is true for the other two digits.   Thus the sum is:   9x100+9x500+9x800+9x10+9x50+9x80+9x1+9x5+9x8=   999x(1+5+8)=999x14=13986   13986
<result>E</result>
What is the sum of all 3 digit positive integers that can be formed using the digits 1, 5, and 8, if the digits are allowed to repeat within a number?