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anonymous
 one year ago
Find the sum of the first 20 even numbers.
Write a sequence that shows the first 20 even numbers.
anonymous
 one year ago
Find the sum of the first 20 even numbers. Write a sequence that shows the first 20 even numbers.

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anonymous
 one year ago
Best ResponseYou've already chosen the best response.02+4+6+8+10+12+14+16+18+20+22+24+26+28+30+32+34+36+38+40= 422?

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0Possibly? Unless there's another part to this question that we're missing

madhu.mukherjee.946
 one year ago
Best ResponseYou've already chosen the best response.2The first 20 even numbers are: 2,4,6,8,10,12,14,16,18,20,22,24,26,28,3... Gauss's method for the sum is as follows: The sum is: 2+4+6+8+10+12+14+16+18+20+22+24+26+28+3... That would take a while to type into a calculator (or do by hand) and you might make a mistake. Gauss noticed that if you write that out again, underneath the original and in reverse: 2 +4 + 6+ 8+ 10+12+14+16+18+20+22+24+26+28+30+32+34+3... 40+38+36+34+32+30+28+26+24+22+20+18+16+... 8+ 6+ 4+ 2 Then looking at the numbers above and below eachother, and summing them in turn, you get: (2+40) + (4+38) + (6+36) +...+ (36+6) + (38+4)+(40+2) Sum the figures in brackets: (42) + (42) + (42) + ... + (42) + (42) + (42) They're all the same, and equal to 42. We know there are twenty of them, so the sum of twice the original series can be quickly calculated as: 20 x 42 = 840. So we can deduce that the sum of the first twenty even numbers is 840/2 = 420.

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0That copy/paste tho lol

anonymous
 one year ago
Best ResponseYou've already chosen the best response.0thank you sooo much both of you

madhu.mukherjee.946
 one year ago
Best ResponseYou've already chosen the best response.2your welcome
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