Sum of two rational numbers is - 8 is 3 by 4 find others

Evaluate 4 a for a = 5 2/3 . express your answer in simplest form.

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.

Because of your favorite lemonade it is $3.84 for 3 gallons. write this as an unit rate