Question

What I’d the sum of the numbers 1 up to 200

Answer 1

SOLUTION

The given sum of numbers are

$1+2+3+4+5+\cdots+200$

Notice that this represents an arithmetic series with

First term a=1

Last term l=200

Number of terms n = 200

Using the arithmetic sum formula

$S_n=\frac{n}{2}\lbrace a+l\rbrace$

Substituting values gives

$\begin{gathered} S_n=\frac{200}{2}(1+200) \\ S_n=100(201) \\ S_n=201,100 \end{gathered}$

Therefore the total sum is 201,100