There is a formula to calculate this sum. It is, S = ½n(n + 1) In this question, n = 25 so the sum of the numbers from 1-25 is, ½ x 25 x 26 = 325
The sum of the even numbers is (26 + 28 + ... + 100); The sum of the odd numbers is (25 + 27 + ... + 99) Their difference is: (26 + 28 + ... + 100) - (25 + 27 + ... + 99) = (26 - 25) + (28 - 27) + ... + (100 - 99) = 1 + 1 + ... + 1 There are (100 - 26) ÷ 2 + 1 = 38 terms above which are all 1; their sum is 38 x 1 = 38. So the difference of the sum of all even numbers and all odd numbers 25-100 is 38.
The sum of all the numbers 1 through 200 is 20,100.
The sum of the all prime numbers from 1 to 100 is 1,161
The sum of all odd numbers 1 to 120,000 is 14,400,000,000.
There is a formula to calculate this sum. It is, S = ½n(n + 1) In this question, n = 25 so the sum of the numbers from 1-25 is, ½ x 25 x 26 = 325
The sum of the even numbers is (26 + 28 + ... + 100); The sum of the odd numbers is (25 + 27 + ... + 99) Their difference is: (26 + 28 + ... + 100) - (25 + 27 + ... + 99) = (26 - 25) + (28 - 27) + ... + (100 - 99) = 1 + 1 + ... + 1 There are (100 - 26) ÷ 2 + 1 = 38 terms above which are all 1; their sum is 38 x 1 = 38. So the difference of the sum of all even numbers and all odd numbers 25-100 is 38.
1+3+5+7+9=25
The sum of all the numbers 1 through 200 is 20,100.
Sum of 1,2, ... , n is n*(n+1)/2 Here, n = 25 so sum = 25*26/2 = 325
The sum of all the odd numbers between 1 and 12000 is 36000000.
The sum of the all prime numbers from 1 to 100 is 1,161
The sum of all odd numbers 1 to 120,000 is 14,400,000,000.
The numbers are 13 and 12
The sum of all the odd numbers from 1 through 100 is 10,000
The sum of all prime numbers between 1 and 11 is 28.
The sum of all odd numbers 1 through 99 is 9,801.