Question 952916
For this problem you have to use permutations. You can see how many permutations there are in total which is 9*10*10*10*10=90,000. This is the case since the first value can be any number from 1-9 and all the other values can be any number 0-9. The values which do not have a six in them are 8*9*9*9*9= 52,488. This is the case since the first number is any number but 6 and 0, all the other numbers are any number but 6. Thus if we subtract the two values we get the number that exactly one six in them which is 90,000-52,488 = 37,512 which is the answer.