Find the sum of all even numbers between 2 & 200 inclusive, excluding those which are multiples of 3. Sum of even numbers, is it means the series of 2 + 4 + 6 + ….+ 200? Excluding multiples of 3, is it means 6 + 12 + 18 +....+ 198?
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Originally Posted by geton Find the sum of all even numbers between 2 & 200 inclusive, excluding those which are multiples of 3. Sum of even numbers, is it means the series of 2 + 4 + 6 + ….+ 200? Excluding multiples of 3, is it means 6 + 12 + 18 +....+ 198? It effectively means (2 + 4 + 6 + ….+ 200) - (6 + 12 + 18 +....+ 198)
Originally Posted by mr fantastic It effectively means (2 + 4 + 6 + ….+ 200) - (6 + 12 + 18 +....+ 198) Yes I found my mistake. My mistake was n/3 [2a + (n-1)d] instead of n/2 [2a + (n-1)d]. Thank you.
Originally Posted by geton Find the sum of all even numbers between 2 & 200 inclusive, excluding those which are multiples of 3. Sum of even numbers, is it means the series of 2 + 4 + 6 + ….+ 200? Excluding multiples of 3, is it means 6 + 12 + 18 +....+ 198? { :2≤ ≤200 }
Originally Posted by geton Yes I found my mistake. My mistake was n/3 [2a + (n-1)d] instead of n/2 [2a + (n-1)d]. Thank you. Between 2 and 200, that means 2 and 200 are not included right?
Originally Posted by SengNee Between 2 and 200, that means 2 and 200 are not included right? between 2 & 200 inclusive
Originally Posted by geton Find the sum of all even numbers between 2 & 200 inclusive, excluding those which are multiples of 3. Sum of even numbers, is it means the series of 2 + 4 + 6 + ….+ 200? Excluding multiples of 3, is it means 6 + 12 + 18 +....+ 198? Here is an easier way to sum.
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