I solve it like this in first but after , I think this solution is correct :Ahh, I missed that each combination must include a letter. Your calculation looks reasonable. It should produce the same result if you subtract 10•10•10 from 36^3?
Thanks a lot for help , so are you sure about your answer ?36^3 = 46,566
10^3 = 1,000
So I don't think your approach is correct now that I have checked it.
There are formulas for this, you know. One thing you want to learn is where to find them and how to use them. You might even be expected to remember a few of them and produce them on an exam.
But why my solution is wrong ?I have no dog in the fight. You're the one that needs to be sure.
This might help.
https://www.mathsisfun.com/combinatorics/combinations-permutations-calculator.html
Ok , thank you so much really appreciate it .It incorrectly double and triple counts some of the permutations. In your summing, many permutations can occur in each of the three components of the sum.
It's not unusual to be confused by this stuff! If you want to blow your mind, look up the "Monty Hall problem".Ok , thank you so much really appreciate it .
I think Waynes approach is correct.But why my solution is wrong ?
by Jake Hertz
by Robert Keim
by Jake Hertz
by Jeff Child