Question 101125: 1,3,5,7,9,11,13,15,17,19 these are 10 numbers and there sum is 100 select 5 from these numbers and there sum is 50
Answer by bucky(2189)   (Show Source):
You can put this solution on YOUR website! If I understand your problem correctly, this can't be done.
.
My understanding is that you are given the numbers:
.
1, 3, 5, 7, 9, 11, 13, 15, 17, and 19
.
You are to select 5 of these numbers such that the total of the 5 numbers you select is 50.
.
Notice that all the numbers are odd numbers. When you add two odd numbers together the sum
is always an even number. And if you also add four odd numbers together you always get an even
number for the sum.
.
That means that if you pick four numbers from the above list and add them you will get an
even number as an answer. Therefore, your fifth number will need to be an even number
to get to 50. But you have no even numbers to choose from for the fifth number.
.
For example, suppose we choose as our 4 numbers 1, 3, 17, and 19. If we total these
four numbers we get 40 and 40 is an even number. Therefore, to get to 50, our fifth number
would have to be and even number, in this case 10, so it is not in the list of numbers we
have to choose from. You can try any other combination of four numbers from the list. If
you add them up you will get an even number, and presuming their sum is less than 50,
you will need to add an even number to that group of four to get a total of 50. But, again,
you do not have an even number in the list, so you cannot get five numbers from the list
of odd numbers to total to 50.
.
Hope this helps you to understand why the problem can't be solved.
.
|
|
|
