C++ How can I modify my existing code (in last photos) to meet the new requirements in the photos I’ve attached first?

My code is long because I’ve added a bunch of comments to clear up any confusion. Thank you!!!

The “rule of 72” is used to approximate the time required for prices to double due to inflation. if the inflation rate is r%, then the rule of 72 estimates that prices will double in 72/r years. for instance, at an inflation rate of 6%, prices double in about 72/6 or 12 years. write a program to test the accuracy of this rule. for each interest rate from 1% to 20%, the program should display the rounded value of 72/r and the actual number of years required for prices to double at an r% inflation rate. (assume prices increase at the end of each year.)

Knowing that the central portion of link bd has a uniform cross sectional area of 800 mm2 , determine the magnitude of the load p for which the normal stress in link bd is 50 mpa. (hint: link bd is a two-force member.) ans: p = 62.7 kn

Which of the following would you find on a network