There are <u>120</u> of 3-digit descending numbers in total.
There is just one three-digit number that is a falling number if 2 is in the hundreds position, and that number is 210.
There are three such descending numbers if the number three is in the hundreds location.
310
320
321
Six descending numbers are available if 4 is in the hundreds place.
410
420
421
430
431
432
We have 10 descending numbers if the number five is in the hundreds location.
510
520
521
530
531
532
540
541
542
543
The current totals are: 1, 3, 6, and 10.
A +2 jump occurs from 1 to 3.
There is a +3 jump from 3 to 6.
From 6 to 10, there is a +4 jump.
Since there are 15 descending numbers and 6 is the hundreds digit, they are as follows: 610 620 621 630 631 632 640 641 642 643 650 651 652 653 654
Also included are the descending numbers 15+6 = 21 with the hundreds digit 7; 21+7 = 28 with the hundreds digit 8; and 28+8 = 36 with the hundreds digit 9.
They are 1,3,6,10,15,21,28, and 36.
1+3+6+10+15+21+28+36.
Equals 120 when added together.
Thus, there are <u>120</u> of 3-digit descending numbers in total.
Learn more about descending numbers at
brainly.com/question/13193576
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