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16 votes
16 votes
What is the sum of all integers between:
✓11 and 39

User Mychelle
by
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1 Answer

18 votes
18 votes

Answer:

The sum of all integers is 774.

Explanation:

Since √11 = 3.3166, and 3.3166 is not an integer, so the first integer is 4.

From 1 to 39, there are 39 integers. But we started with 4, so we take out 3 numbers (1, 2, 3). Therefore, there are 39 - 3 = 36 numbers left.

The total number between 4 and 39 is 36 = n.

Sn = n/2 x (a1 + an)

S36 = 36/2 x (4 + 39) = 18 x 43 = 774

User Iterator
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