SOLUTION: How many three-digit numbers have the sum of their digits equal to 20? This is a homework problem for me and I am simply stumped. we are working on permutations, factorials and

Question 243582: How many three-digit numbers have the sum of their digits equal to 20?
This is a homework problem for me and I am simply stumped. we are working on permutations, factorials and trees.
Thank you!!
Answer by checkley77(12844) (Show Source): You can put this solution on YOUR website!
I count 36.
992=20
983=20
974=20
965=20
956=20
947=20
938=20
929=20
893=20
884=20
875=20
866=20
857=20
848=20
839=20
794=20
785=20
776=20
767=20
758=20
749=20
695=20
686=20
677=20
668=20
659=20
596=20
587=20
578=20
569=20
497=20
488=20
479=20
398=20
389=20
299=20

RELATED QUESTIONS
how many three digit numbers have the sum of their digits equal to... (answered by josmiceli)

how many two digit numbers with their tens digit greater than their unit digit,have the... (answered by Edwin McCravy)

How many 3 digit numbers are there that have the sum of their digits equal to 5. For... (answered by ikleyn)

I can only remember a seven-digit telephone number if the first three digits (the... (answered by CPhill,ikleyn)

Hello. I am stuck with this question and have no idea how to start it. Here it is: A... (answered by Alan3354,MathTherapy)

Hi much appreciated math tutors. I am very frustrated by this problem... In a given... (answered by Boreal)

This word problem is stumping me. I can't figure out how to write the equations needed... (answered by longjonsilver)

How many 3-digit numbers have the product of their digits equal to... (answered by stanbon)

I am a seven digit even number. The sum of my digits is 31. The ones,hundreds and ten... (answered by richard1234)