so, start with 1xxx. With various values of d, we get
d=1: 1234, 2345, 3456, 4567, 5678, 6789
d=2: 1357, 2468, 3579
d=3: 147? bzzt
Now, with negative d, we have
d=-1: 9876, 8765, 7654, 6543, 5432, 4321, 3210
d=-2: 9753, 8642, 7531, 6420
d=-3: 9630
So, of the numbers listed, how many are not multiples of 1111?
In how many positive four-digit integers that are not multiples of 1111 do the digits form an arithmetic sequence? (The digits must form an arithmetic sequence, in order. For example, the number 5137 does not count.)
5 answers
6+7+4+1+3=21
STEVE YOU MSUT HAVE POOP FOR BRAINS!
Agree that the answer is 21
Yes, I checked. The answer is 21.