please show your work
2007-05-15 13:46:45 · 10 answers · asked by krutilcody 2 in Science & Mathematics ➔ Mathematics
1 + 3 + 5 + ....
notice 1 + 3, the 1st 2, add up to 4.
1 + 3 + 5, the 1st 3, add up to 9.
1 + 3 + 5 + 7, the 1st 4, add up to 16, which is 4², just as 9 is 3² and 4 is 2². So the sum of the 1st 100 is 100² = 10,000.
2007-05-15 13:50:21 · answer #1 · answered by Philo 7 · 0⤊ 0⤋
Use a pattern.
The formatting doesn't work, but just line up the numbers one under the other to add the two equations...
s = sum
s = 1 + 3 + 5 + 7 ... + 193 + 195 + 197 + 199
s = 199 + 197 + 195 + 193 ... + 7 + 5 + 3 + 1
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2s = 200 + 200 + 200 + 200 ... + 200 + 200 + 200 + 200
so, 2s = 200(100)
2s = 20 000
s = 10 000
2007-05-15 13:58:59 · answer #2 · answered by some_person 1 · 0⤊ 0⤋
5 odd numbers can never sum to 100. They will always give an odd number as an answer.
2016-05-19 14:58:22 · answer #3 · answered by jessica 4 · 0⤊ 0⤋
Ok, my bad, I did for the first 100 numbers.
199+1=200, etc.
50 odd numbers from 1-99, so there are 50 pairs of the odd numbers (eg, 41+159, 91+109, etc.)
So 50*200=10000.
2007-05-15 13:59:12 · answer #4 · answered by Anonymous · 1⤊ 0⤋
50(1+199) = 10000
2007-05-15 13:51:00 · answer #5 · answered by B-Mar 3 · 0⤊ 0⤋
t=1+(99)2=199
s=(100/2)(1+199)=(50)(200)= 10,000
Answer: 10000
2007-05-15 13:52:17 · answer #6 · answered by ZAxel 2 · 0⤊ 0⤋
1+3+5+7+9+11+13+15+17+19+21+...99= come on your can figure it out.
2007-05-15 13:50:22 · answer #7 · answered by JGN 2 · 0⤊ 1⤋
would've been funnier if it was the sum of the first 100 prime numbers:P
the answer is correct..above
2007-05-15 13:55:55 · answer #8 · answered by Bladvak 3 · 0⤊ 0⤋
10,000
2007-05-15 13:51:12 · answer #9 · answered by Anonymous · 0⤊ 1⤋
10,000
2007-05-15 13:52:07 · answer #10 · answered by smokefanTS20 3 · 0⤊ 2⤋