Answer :
SAME HERE...IT ALSO CANT BE CREDITED TO ANONE...AS PEOPLE IN OLD TIME WERE UNEDUCATED...SINCE..SOME PARENT,,ORGANISE TEACHER WHO CAME AND TEACH CHILD AT HOME..THEN..SOME SAINT STARTED TEACHING CHILDEN GENERALLY UNDER TREES...CHILDREN GATHER UNDER TREES AND TEACHER TEACH THEM...THEN THIS SYSTEM STARTED TO BE DONE IN BUILDINGSI.E. SCHOOLS ...IN WHICH WE WENT NOW TO LEARN