Sarah has $400 in a savings account at the beginning of the summer. She wants to have at least $100 in the account by the end of the summer. She withdraws $20 each week for fun. How many weeks can Sarah withdraw money from her account? how would I write this in inequality ​

He ! a group of farmers planned to clean 80 acres of wheat per day to finish the work on schedule. right before the work started, they received a new piece of machinery that them clean 10 more acres per day than originally planned. as a result of increased productivity in the last day before the deadline they only had to clean 30 acres. how many acres of wheat did the group of farmers have to clean?