1+2=3
1+2+3=6
1+2+3+4=10
1+2+3+4+5=15
1+2+3+4+5+6=21
...etc...
1+2+......+24+25=325.
Another approach is:
Sum=(25+1)*25/2=325.
(1+25)times25 then divided in half.13 times 25=325
The sum of all integers between 1 and 25 is equal to (25 x (25 - 1))/2 = 325.
The sum of 1 through 250 is 31,375.
A number is considered abundant if the sum of its proper divisors (excluding itself) is greater than the number itself. For 95, the proper divisors are 1, 5, and 19, which sum to 25. Since 25 is less than 95, the number 95 is not abundant.
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
(1 + 25) x 25/2 ie 425. The sum of the first n integers is (n + 1) x n/2
Yes, 25 is an abundant number because the sum of its proper divisors (1, 5) is greater than the number itself (25 < 6).
(1+25)times25 then divided in half.13 times 25=325
The sum of all integers between 1 and 25 is equal to (25 x (25 - 1))/2 = 325.
I still remember my brother taught me this simple math.... First, add 1 with the last number. So, 50 + 1 = 51 Then divide the last number with 2. So, 50/2 = 25 So, 51 X 25 = 1275 Asraf
The sum of 1 through 250 is 31,375.
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
Sum of 1,2, ... , n is n*(n+1)/2 Here, n = 25 so sum = 25*26/2 = 325
-- The sum of 25 and any positive number. -- The difference of 25 and any negative number. -- The product of 25 and any positive number greater than '1'. -- The ratio of 25 to any positive number less than '1'. -- 25 raised to any positive power greater than '1'. -- 25 raised to any negative power less than '1'. -- The factorial of any number greater than 5.
Pr(Sum > 25) = Pr(Spinner = 30 or 40 and Cube = 6) = Pr(Spinner = 30 or 40)*Pr(Cube = 6) = 2/4 * 1/6 = 1/2*1/6 = 1/12 or 8.33... %
25
The sum of the whole numbers 1 through 1,000 is 500,500.