+321 What is the average of all positive integers that have four digits when written in base 3, but two digits when written in base 6? Write your answer in base 10.
+37153 Base 3 largest 4 digit number 2222 = 8010
smallest base 3 number 1000 = 2710
Largest 2-digit base 6 55 = 3510
smallest 10 = 610
So the numbers that are 4 digit in base 3 and 2 digit in base 6 go from 2710 thru 3510 I'll let you finsish from here......
