'Dad, please give me $5000 to buy reference books,' asked John.
'Here you are.But you must not spend it on other things,' said Dad.
a)What is the cost
i)to John's father of giving John the $500?
ii)to John of using the $500? (6marks)
b) Suppose John bought a reference book which he later finds to be useless. Has his cost of buying the reference book increased? Explain your answer. (4marks)