An infinite amount if you include decimals and negative numbers. 2.5+1.5=4
4, if you multiply them.
5
There are 15 of them.
2x2=4
In addition, several pairs of numbers can equal 19. For example, 10 + 9 = 19, and 15 + 4 = 19. Additionally, 18 + 1 and 12 + 7 also sum to 19. Any two numbers that add up to 19 can be considered valid combinations.
4, if you multiply them.
There are infinitely many answers and these depend on what is done with the two numbers: addition, multiplication, exponentiation and so forth.In each case, there are infinitely many answers. For example, with addition,67.2 + 67.267.1 + 67.367.0 + 67.4...0.1 + 134.30.0 + 134.4-0.1 + 134.5-0.2 + 134.6etc.Then you can add numbers to two decimal places, to 3 do, 4 dp, ... infinitely many dp.
5
4
Yes - due to commutability, you can rearrange the numbers in any addition sum and the answer will still be the same.
There are 15 of them.
1+2+3+53 is one quartet. There are an infinite number of possible quartets for addition alone. And then you can have sutractions. And then multiplications, and divisions.
This is not possible, 27 is an odd number, 4 odd numbers will always equal an even number.
143
20
2x2=4
In addition, several pairs of numbers can equal 19. For example, 10 + 9 = 19, and 15 + 4 = 19. Additionally, 18 + 1 and 12 + 7 also sum to 19. Any two numbers that add up to 19 can be considered valid combinations.