2007-12-11 06:26:43 · 34 answers · asked by Jonathan S 2 in Science & Mathematics ➔ Mathematics
formula
n(n+1) =25*26=650
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as the sum of the 1st 25 numbers
1,2,3,4,5......,25
=25*26/2
the even number = this sum *2 =25*26
2007-12-11 06:40:17 · answer #1 · answered by mbdwy 5 · 2⤊ 0⤋
0 + 2 + 4 + 6 + 8 + 10 + 12 + 14 +16 +8 +20 + 22 + 24 + 26 + 28 + 30 + 32 +34 +36 + 38 + 40 +42 + 44 + 46+ 48
= 668
2007-12-12 07:51:12 · answer #2 · answered by Rayan Ghazi Ahmed 4 · 0⤊ 2⤋
2 + 4 + 6 + 8 + 10 = 30
12 + 14 + 16 + 18 + 20 = 80
22 + 24 + 26 + 28 + 30 = 130
just 1 to 25 even is 156
32 + 34 + 36 + 38 + 40 = 180
42 + 44 + 46 + 48 + 50 = 230
650
do you see the pattern that develops?
2007-12-11 06:33:22 · answer #3 · answered by Jim L 3 · 1⤊ 0⤋
Sum Of First 50 Even Numbers
2016-11-10 08:54:15 · answer #4 · answered by Anonymous · 0⤊ 0⤋
2+4+6+8+10+12+14+16+18+20+22+24+26+28+30+32+34+36+38+40+42+44+46+48+50=650 That is the corroect answer.
2007-12-11 06:33:05 · answer #5 · answered by Anonymous · 0⤊ 1⤋
The first 25 even numbers are the even numbers starting at 2 and ending at 50. One easy way to add up lists of numbers like this is like follows:
50
48+2 = 50
46+4
44+6
42+8
40+10
38+12
36+14
34+16
32+18
30+20
28+22
26+24
As you can see, there are 13 sets of even numbers totaling 50 each. So, just multiply.
50*13 = 650
This works for adding any series of numbers. For example, the sum of the numbers between 1 and 100 is (100+1) * 50 or 5050.
2007-12-11 06:44:17 · answer #6 · answered by John73 5 · 1⤊ 0⤋
2+4+6+8+10+12+14+16+18+20+22+24+26+28+30+32+34+36+38+40+42+44+46+48+50= 650
2007-12-11 06:30:53 · answer #7 · answered by dulaney78 1 · 2⤊ 1⤋
2+4+6+8+10+12+14+16+18+20+22+24+26+28+30+32+34+36+38+40+42+44+46+48+50= 650
2007-12-11 06:30:32 · answer #8 · answered by donkeypunch'em 3 · 2⤊ 1⤋
The first even number is 2.
The 25th even number is 50.
The 13th even number is 26.
There are 12 numbers before and after the 13th no.
Therefore: (50+2) x 12 + 26 = 624 + 26 = 650.
2007-12-11 06:41:01 · answer #9 · answered by rkeech 5 · 2⤊ 0⤋
2 + 4 + 6 + ... + 50
=2 ( 1 + 2 + 3 + ... + 25 )
=2 ( 25 ) ( 25 + 1 ) / 2
=( 25 ) ( 25 + 1 )
=650
2007-12-11 06:30:58 · answer #10 · answered by jgoulden 7 · 4⤊ 0⤋