Question 1155803
The sum of 39 consecutive number is 1170, what is the largest of these 39 number could be?
<pre>Being consecutive numbers, this is an A.P.
With the equation for the sum of an A.P. series being: {{{matrix(1,3, S[n], "=", (n/2)(2a[1] + (n  -  1)d))}}}, we get:
                                                     {{{matrix(4,3, S[39], "=", (39/2)(2a1 + (39  -  1)1),
"1,170", "=", (39/2)(2a[1] + 38),
39(30), "=", 39(a[1] + 19), 
30, "=", a[1] + 19))}}}
                                                     1st term, or {{{highlight_green(matrix(1,5, a[1], "=", 30  -  19, "=", 11))}}}
n<sup><b>th</sup></b> term of an A.P.: {{{matrix(1,3, a[n], "=", a[1] + (n  -  1)d)}}}
                    {{{matrix(1,3, a[39], "=", 11 + (39  -  1)1)}}} ------ Substituting 39 for n, 11 for {{{a[1]}}}, and 1 for d
Last/Largest term/number, or {{{highlight_green(matrix(1,5, a[39], "=", 11 + 38, "=", 49))}}}