Explanation:

According to census, "Work" is defined as participation in any economically productive activity with or without compensation, wages or profit. Such participation may be physical and/or mental in nature. Work involves not only actual work but also includes:

• effective supervision and direction of work;
• part time help or unpaid work on farm, family enterprise or in any other economic activity; and
• cultivation or milk production even solely for domestic consumption.

Hence only 1 and 3 can be classified as a worker as per Indian census classification.

•  Women working as a part time worker in a family enterprise without any wages. Though they are not earning any remuneration but they are engaged in an economic activity thus they are considered as a worker.
•   Women who are bringing woods from Forest for self cooking purposes are not considered worker since they are not doing any economic activity. If they have been cooking food for selling purpose than they would be considered as worker.
•  16 year old adolescent working in family owned tea stall is involved in an economic activity thus he is considered as a worker. 
• 70 year old man watering the community Park without any remuneration is not a worker, since he is watering the Park as a social service. He is not engaged in an economic activity. A professional gardener watering park and who is also paid for it can be considered a worker, since he is not doing social service and there is an economic angle involved in it.