How do I solve these problems?

At dinner, 2/5 of the people had fish and 1/3 had chicken. if everyone else had lamb, what fraction of the people had lamb? and if 40 people had lamb , calculate the total number of people at the dinner.

Jack is considering a list of features and fees for denver bank. jack plans on using network atms about 4 times per month. what would be jack’s total estimated annual fees for a checking account with direct paycheck deposit, one overdraft per year, and no 2nd copies of statements?

What is the measure of one interior angle of a pentagon