Question

Please help!! fans/medals
Jennifer has been saving for college for 57 months. The first month she saved $11. She was able to save more money each month than the month before. She ended up saving $19,779.00. How much more did she save each month?

Answer 1

@ranga

Answer 2

" She was able to save more money each month than the month before."
Assume her monthly savings follows an arithmetic sequence and that she saves "d" dollars more each month:
11, 11+d, 11+2d, 11+3d, ......., 11+56d
The last term is 11+56d because she saves for 57 months.
The sum of an arithmetic progression is: (first term + last term) / 2 * n
where n is the total number of terms which is 57
Sum = { 11 + 11 + 56d } / 2 * 57 = 19,779
(11 + 28d) * 57 = 19779
divide both sides by 57.
The subtract 11 from both sides
divide both sides by 28 and solve for d.