Can you find a quick and elegant way to add the numbers from 1 to 36 ? In other words, what is the sum you obtain in the following case: 1 + 2 + 3 + ....... + 36 =

To find the sum of the numbers from 1 to 36, there is a formula that can be used. This formula is known as the arithmetic series formula:

$$S = \frac{n}{2}(a + l)$$

Where:

• S is the sum of the series
• n is the number of terms in the series
• a is the first term of the series
• l is the last term of the series

In this case, we have:

• n = 36 (as we are adding the numbers from 1 to 36)
• a = 1 (the first term of the series)
• l = 36 (the last term of the series)

Substituting these values into the formula:

$$S = \frac{36}{2}(1 + 36)$$

$$S = 18(37)$$

$$S = 666$$

Hence, the sum of the numbers from 1 to 36 is 666.

Therefore, the correct answer is: C. 666