A rectangular barn door needs to be painted. The door is 81 inches high and 50 inches wide. What is the area of the front of the door?
А
8,100 square inches
B
1,620 square inches
524 square inches
D 4,050 square inches

Asays "we are both knaves" and b says nothing. exercises 24–31 relate to inhabitants of an island on which there are three kinds of people: knights who always tell the truth, knaves who always lie, and spies (called normals by smullyan [sm78]) who can either lie or tell the truth. you encounter three people, a, b, and c. you know one of these people is a knight, one is a knave, and one is a spy. each of the three people knows the type of person each of other two is. for each of these situations, if possible, determine whether there is a unique solution and determine who the knave, knight, and spy are. when there is no unique solution, list all possible solutions or state that there are no solutions. 24. a says "c is the knave," b says, "a is the knight," and c says "i am the spy."

Evaluate the expression for the given value of the variable. 5×(h+3) for h=7

How to do this , and can some one explain