Table of Contents
What are multiplication problems that equal 21?
3 x 7 = 21. 7 x 3 = 21. 21 x 1 = 21.
How do you play 21 for beginners?
Play basic strategy
- Stand when your hand is 12-16 when the dealer has 2-6.
- Hit when your hand is 12-16 when the dealer has 7-Ace.
- Always split Aces and 8s.
- Double 11 versus the dealer’s 2-10.
- Hit or double Aces-6.
What 4 numbers add up to 21?
Good luck! Hence the 4 numbers are 4, 12, 20 and 64.
What is the sum of the factors of 21?
32
Therefore the factors of 21 are 1, 3, 7 and 21. All that is left to do is to work out the sum of these numbers, that is to add them all up. 21+1 + 3 +7 = 32Therefore, the sum of the factors of 21 is 32.
How do you work out 2/3 of a number?
To find 2/3 of a whole number we have to multiply the number by 2 and divide it by 3. To find two-thirds of 18, multiply 2/3 x 18/1 to get 36/3.
Is 21 = (1+2+4)*3?
With 2 and 4 it doesn’t work, so we can have 21= [1,2,4]*3 or 7= [1,2,4]. The only combination in this variant is to have 7=1+2+4 and thus 21= (1+2+4)*3. It seems from another answer that even doing this isn’t enough. Let’s try to factor 21. It is 3*7, maybe 1*3*7 though this doesn’t help.
How do you get 21 from 2x2x3x4?
Basically, what you need to do is find a way to multiply/add the numbers so they give you 21. If you multiply them all by each other; 1 x 2 x 3 x 4, they give you 24. If you add them all together: 1 + 2 + 3 + 4, they give you 10.
What is the easiest way to find 21 from 20 and 1?
It’s quite simple. Then add 20 + 1 = 21. Basically, what you need to do is find a way to multiply/add the numbers so they give you 21. If you multiply them all by each other; 1 x 2 x 3 x 4, they give you 24.
How many numbers can you use only 1 2 3 and 4?
You can use only the digits 1, 2, 3 and 4 once in each and the operations + – * / . So, here goes… 1 to 50, using only 1, 2, 3 and 4 and the basic maths operators. Some of the answers seem a little repetitive or derivative (look at 38 through 43), and in some cases I found alternative answers afterwards.