How do i justify my answer for an absolute maximum in calculus?

The gades foundation and hbm corporation are eager to donate generously to their favorite charities. the gades foundation donated $250 in the first month, and each month afterward their cumulative donation total increases by 100$ the hbm corporation donated $64, in the first month, and each month afterward their cumulative donation total increases by 75%. in which month will the hbm corporation's cumulative donation total first exceed the gades foundations' cumulative donation total?

At a kentucky friend chicken, a survey showed 2/3 of all people preferred skinless chicken over the regular chicken. if 2,400 people responded to the survey, how many people preferred regular chicken?

If i had 1234 apples and 1 banana what is the total amount