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The sum of all numbers from 8 to 18 is an even number?
If you include 8 and 18 that is 11 numbers and their sum is 143 which is odd ---- Explanations (by the way, it is really not all the numbers between 8 and 18, it is just all the integers. There is an infinite number of numbers between 8 and 18, think of just 8, 8.1, 8.11, 8.111, 8.1111 etc) Here are some other fun ways to do this: One way to do it, of course is just to add 8+ 9 10 11 12 13 14 15 16 17 18 Before you add them all, consider just adding the last column, and looking at the ones column of that number. 8+9+0+1+2+....+8 that number is 53 so the sum is odd. If that numbers is even then the number is even OR Looking at just the odd numbers. The sum of even numbers is always even. An odd number and an even number is an odd number. So if the sum of the odd numbers is even then the last column will be an odd number and the total sum will be odd. The sum of odd numbers is even when there is an even number of them. Look at 2 odd numbers. (ie 3+3 =6, this is two odd numbers and their sum is even) 9,11,13,15,17 are even and there are 5 of them. This is an odd number of odd so the sum is odd. Now we know the sum of the odds and the evens is odd so the total of the last column must be odd and therefore the sum is odd. Another way is to see that the sum of the first n numbers is n(n+1)/2 We can add the sum of the first 18 numbers then subtract the sum of the first 7 numbers and what is left is the sum of the numbers 8 to 18. So in this case we have 18x19/2-8x9/2 which is (18x19-7x8)/2 this simplifies by first dividing the 18 and the 8 by 2 so we have 9x19-4x7= 171-28=143 OR What if we match up and add the 8 and the 18, the 9 and the 17, the 10 and the 16, the 11 and the 15, the 12 and the 14 and you have 13 left. This is the idea behind the formula for the first n numbers. That is 26x5+13=143
What is the sum of two numbers between 20 and 40 that is 58 and will equal 12 if subtracted?
The sum of two numbers between 20-40 is 58. The difference is 12
Find the total of the odd numbers between 6 and 12?
there are 3.... 7,9,11
Is the sum of 3 numbers always odd?
No! 1 + 2 + 3 = 6 2 + 4 + 6 = 12 even
If the product of 2 even numbers is even then the 2 numbers must be even?
This is not always true. If the sum of two numbers is even, then those two numbers are either both even or both odd. For example: 2 + 2 = 4 (even + even = even) 5 + 7 = 12 (odd + odd = even) 3 + 2 = 5 (odd + even = odd)
What is the sum of 12 using three odd numbers?
Cant be done
What three different odd numbers make 20?
To make 20 with three different odd numbers, we can use the numbers 1, 7, and 12. 1 + 7 + 12 = 20. These numbers are odd because they cannot be evenly divided by 2. It's important to note that there are multiple combinations of three odd numbers that can add up to 20, such as 3 + 9 + 8 or 5 + 11 + 4.
The sum of all numbers from 8 to 18 is an even number?
If you include 8 and 18 that is 11 numbers and their sum is 143 which is odd ---- Explanations (by the way, it is really not all the numbers between 8 and 18, it is just all the integers. There is an infinite number of numbers between 8 and 18, think of just 8, 8.1, 8.11, 8.111, 8.1111 etc) Here are some other fun ways to do this: One way to do it, of course is just to add 8+ 9 10 11 12 13 14 15 16 17 18 Before you add them all, consider just adding the last column, and looking at the ones column of that number. 8+9+0+1+2+....+8 that number is 53 so the sum is odd. If that numbers is even then the number is even OR Looking at just the odd numbers. The sum of even numbers is always even. An odd number and an even number is an odd number. So if the sum of the odd numbers is even then the last column will be an odd number and the total sum will be odd. The sum of odd numbers is even when there is an even number of them. Look at 2 odd numbers. (ie 3+3 =6, this is two odd numbers and their sum is even) 9,11,13,15,17 are even and there are 5 of them. This is an odd number of odd so the sum is odd. Now we know the sum of the odds and the evens is odd so the total of the last column must be odd and therefore the sum is odd. Another way is to see that the sum of the first n numbers is n(n+1)/2 We can add the sum of the first 18 numbers then subtract the sum of the first 7 numbers and what is left is the sum of the numbers 8 to 18. So in this case we have 18x19/2-8x9/2 which is (18x19-7x8)/2 this simplifies by first dividing the 18 and the 8 by 2 so we have 9x19-4x7= 171-28=143 OR What if we match up and add the 8 and the 18, the 9 and the 17, the 10 and the 16, the 11 and the 15, the 12 and the 14 and you have 13 left. This is the idea behind the formula for the first n numbers. That is 26x5+13=143
Which pair of numbers has an odd product and an even sum 6 9 12 15?
Must be the 2 odd numbers, 9 & 15 (P = 135, S = 24)
What is the sum of two numbers between 20 and 40 that is 58 and will equal 12 if subtracted?
The sum of two numbers between 20-40 is 58. The difference is 12
I am an odd number between 50 and 60 the sum of your digit is 12 what number are you?
57
Find the total of the odd numbers between 6 and 12?
there are 3.... 7,9,11
What odd whole numbers have 12 as a factor?
No odd whole numbers have 12 as a factor. 1 and 3 are odd numbers that are factors of 12.
Which are the Consecutive Numbers Whose Sum Is 22?
Any pair of consecutive numbers will have an odd total. 10 and 12 are consecutive even numbers that total 22.
What are the sum of the prime numbers between 12 and 48?
89
What is the sum of the prime numbers that are between 12 and 42?
210
What will be the sum of first 25 even numbers?
There are 12 even numbers between 2 and 24 inclusive.The sum is 154.
