Question

Find the sum of the even integers from 20 to 50.with solutions please help​

Answer 1

Answer: 560

Step-by-step explanation:

There are [20, 22, 24, 26, 28]: 5 even integers for each ten numbers.

The 20's set can be written as 5*20 + (2+4 + 6 + 8) = 5*20 + (20) = 120

The 30's can be written: 5*30 + 20 = 170

40's: 5*40+20 = 220

50's: 5*50+20 = 270

60's: 5*60+20 = 320

Each set is incremented by 50

We want the sets for 20, 30, and 40, plus the number 50.

(120+170+220+50) = 560

You can also do this in Excel (attached). Set the first cell to 20, the next cell below equal to the cell above plus 2. Then draw the second cell down until you've reached 50. Then sum the cells to arrive at 560.