You MULTIPLY! "Per" means "divided by" so to go from square feet per seat to square feet you need to do the opposite of "divide by the number of seats" which is "multiply by the number of seats".
If there is to be "5 square feet of kitchen space per restaurant seat" and there are 40 restaurant seats then you need 5(40)= 200 square feet of kitchen space. Is 20 square meters greater than 200 square feet?
You are told that 1 square meter is 10.76 square feet. So how many square feet is 20 square meters? Again, multiply!