What is the sum of even numbers from 3 to 85? Here we will show you step-by-step how to calculate the sum of even numbers from 3 to 85.
Step 1) We start by finding the first (F) and last (L) even numbers from 3 to 85. It is easy to do that by simply looking at the numbers. The first even number is 4, and the last even number is 84.
F = 4
L = 84
Step 2) Next, we calculate the total even numbers (T) there are from 3 to 85, using a formula. Here is the formula and the math:
T = (L - F + 2) ÷ 2
T = (84 - 4 + 2) ÷ 2
T = 82 ÷ 2
T = 41
Step 3) Finally, we use the information from Step 1 and Step 2, and another formula, to calculate the sum of even numbers from 3 to 85, like this:
Sum = (T ÷ 2) × (2 × F + (2 × (T - 1))
Sum = (41 ÷ 2) × (2 × 4 + (2 × (41 - 1))
Sum = 20.5 × (8 + 80)
Sum = 20.5 × 88
Sum = 1804
Sum of even numbers from 3 to 85 = 1804
Sum of Even Numbers Calculator
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