How do you find the sum of $Sigma 5$ where k is [1,5]?

Question

2621 views around the world

You can reuse this answer
Creative Commons License

Answer 1 · 2017-03-17T07:25:45

$sum_"k=1,5" k = 15$

The sum of the first $k$ natural numbers is given by: $(k(k+1))/2$

Hence: $sum_"k=1,5" k = (5(5+1))/2 = (5*6)/2 = 15$

How do you find the sum of Sigma 5Sigma 5 where k is [1,5]?