-8
There is a trick to adding up one through 9
1+9 = 10
2+8 = 10
3+7 = 10
4+6 = 10
5
So the answer is 45 which odd.
The answer to what is the sum of the first positive even numbers is 930. It doesn't mean that you add all the even numbers up until you reach the number 30. In fact, since you have to get the sum of the even numbers, you have to add all even numbers until you get to the number 60.
Find the average. That is, add all of the even numbers together, then divide that by the number of even numbers.
Start with 2, then add 2 at a time, until you reach a million. This will give you all the even numbers.
288. All multiples of 9 will have digits that add to a multiple of 9. To get a multiple of 9 to be all even, you need to get them to add to 18, since no set of even numbers will add up to 9. 288 is the lowest multiple of 9 to be able to add to 18. ■
Apart from 2, all even numbers are composite. So the question is equivalent to all even numbers between 40 and 50. And these are ... ? 42, 44, 46 and 48.
102*25=2550
no...all even numbers that are added together are even.
The answer to what is the sum of the first positive even numbers is 930. It doesn't mean that you add all the even numbers up until you reach the number 30. In fact, since you have to get the sum of the even numbers, you have to add all even numbers until you get to the number 60.
Find the average. That is, add all of the even numbers together, then divide that by the number of even numbers.
Start with 2, then add 2 at a time, until you reach a million. This will give you all the even numbers.
It's 2550
288. All multiples of 9 will have digits that add to a multiple of 9. To get a multiple of 9 to be all even, you need to get them to add to 18, since no set of even numbers will add up to 9. 288 is the lowest multiple of 9 to be able to add to 18. ■
The even numbers between 41 and 47 are 42, 44 and 46.
Apart from 2, all even numbers are composite. So the question is equivalent to all even numbers between 40 and 50. And these are ... ? 42, 44, 46 and 48.
2080
The even numbers between 26 and 36 are 28, 30, 32, and 34.
All even numbers between 50 and 80 are composite.