SOLUTION: 7 + 11 + 15 + 19 + ..... + 55 = ?

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Question 1067054: 7 + 11 + 15 + 19 + ..... + 55 = ?
Answer by Alan3354(69443) About Me  (Show Source):
You can put this solution on YOUR website!
7 + 11 + 15 + 19 + ..... + 55 = ?
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You could add them.
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1 + (55-7)/4 = 13 elements
Make 6 pairs 7 to 51:
7 + 51 = 58
11 + 47 = 58
etc.
--> 6*58 + 55 = 403
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Or,
6.5 pairs 7 to 55
7+55 = 62
11+51 = 62
6.5*62 = 403