For Calc 3 questions, should I submit them into the advanced math section or calculus? Also, what time is best to ask questions for this particular area?

please could you solve the questions  are highlighted with yellow color. please show all work.

Not sure why my answer of undefined is incorrect.

Susan's bioloy class begins with 1225 students. If 5/7 will finish the course and 2/25 of those get a passon grade, how many students will pass Susan's bioloy class this term?

Hello, need some help solving and understanding the following problem.

Still not sure how you came to this answer.  Can you elaborate?

My English is not good. Can you write your handwriting on the computer text?

The word JOURNEY is written over and over again on a long strip of paper (without any blank spaces between words). What letter is the 1389th place counted from the beginning?  how could I come up with an equation to solve this mathmatically?

what is the step to number 4?

How do you do a question like this