4! - 4 + 4/4
The number 21 has only four factors: 1, 3, 7, and 21. Many number have more than four factors. Among them are 1x2x3x4x5 = 120.
21 3,7
One possible solution is: 4.4 + 4 / .4 = 21
As a number it is: 21,064
21+3 or using all the numbers: 21 + (3*(2-1))
4+2+1=7 7*3=21
There is no such number.
If 21 is a factor of a number, then the factors of 21 must also be factors. So 3 and 7
21-2*2-14
23
The number of ways to make 21 depends on the context, such as whether you are referring to combinations of numbers, coins, or other items. For instance, if using coins of different denominations, the number of combinations can vary based on the denominations available. In mathematics, particularly in combinatorics, generating functions or partition functions can be used to calculate the number of ways to express 21 as a sum of integers. If you specify the context or constraints, I can provide a more precise answer.
To make 42 using the number 2, you need 21 twos, since 2 multiplied by 21 equals 42 (2 × 21 = 42). Alternatively, you could also add 2 together 21 times (2 + 2 + ... + 2, twenty-one times) to reach the same total.