Posted by lily on .
The number 3136 is the sum of the first how many odd whole numbers?

Math 543 
Mario,
56

Math 543 
claudia,
how did you solve

Math 543 
Reiny,
so we have
1+3+5+7+... = 3136
let the number of terms of this AS be n
(n/2)(2a +(n1)d) = Sum(n)
So we have a=1, d=2 , and n = ?
(n/2)(2 + (n1)2) = 3136
times 2 ....
n(2 + 2n  2) = 6272
2n^2 = 6272
n^2 = 3136
n = ± 56 , but n has to be a positive whole number,
there are 56 terms