Which of the following set of statements best represents the nature and objective of teaching and learning? 
1) Teaching is like selling and learning is like buying. 
2) Teaching is a social act which learning is a personal act. 
3) Teaching implies learning whereas learning does not imply teaching. 
4) Teaching is a kind of delivery of knowledge while learning is receiving it. 
5) Teaching is an interaction and is triadic in nature whereas learning is an active engagement in a subject domain