assuming you mean positive even numbers, there are 98790 of them. So
S = 98790/2 (2*2 + 98789*2)
do the same, figuring how many odds there are, then summing them up starting with a=1, d=2
The sum of all the even numbers less than and inclusive of E is 197580.
(a) What is the value of E?
(b) What is the sum of all the odd numbers less than E?
4 answers
how do you get 98790 positive numbers?
how many even numbers are there up to 20?
20/2, since they are 2 apart. Count 'em up:
2,4,6,8,10,12,14,16,18,20
If you are going up to n, there are
n numbers
n/2 even numbers (multiples of 2)
n/3 multiples of 3
and so on
20/2, since they are 2 apart. Count 'em up:
2,4,6,8,10,12,14,16,18,20
If you are going up to n, there are
n numbers
n/2 even numbers (multiples of 2)
n/3 multiples of 3
and so on
How do you find the value of E then?