The answer is 20C4 = 20*19*18*17/(4*3*2*1) = 4845
7
20
There are many answers. Here is one: 58 and 20
Including the one in ' 1 ' and the one in '100', there are 21 1s.Every other digit 2 - 9 appears 20 times between 1 and 100 .
6 numbers can go into 20; they are 1, 2, 4, 5, 10 and 20.
There are 38760 combinations.
There are 1140 five digit combinations between numbers 1 and 20.
There are 167960 9 digits combinations between numbers 1 and 20.
There are 1140 5 digit combinations from 1 to 20. 20 combination 3 computes that.
There are 167960 combinations.
There are 125970 combinations and I am not stupid enough to try and list them!
4+4+4+4+4= 20
Twenty factorial which is denoted by "20!". 20! = 1x2x3x4x5x6x7x8x...x19x20
20 There can be two answers to this: I'll assume this is what you meant-> let's say you mean like pairing the numbers 1-5 with the numbers 6-9. 5*4=20
I am assuming you mean 3-number combinations rather than 3 digit combinations. Otherwise you have to treat 21 as a 2-digit number and equate it to 1-and-2. There are 21C3 combinations = 21*20*19/(3*2*1) = 7980 combinations.
There are 45 combinations.
How many combinations of five. Numbers could you get from 1 to 20