please answer by showing all calculation , and formula , everything

Martha has estimated that she would need $35,000 per year (in today's Sterms) to live on in retirement. She will be retiring in 30 years and is funding for a 23-years retirement period. The inflation rate is expected to be 2% per year and the after-tax return on her investments is expected to be 5.5%. Calculate the amount she should save every year starting today in her retirement account to fund her post retirement period. Assume that she has already saved $25,000 in her retirement account. $12.049 $15.489 $13.769 $12,521