Just refer

Working class means,busy class in the world . For example , pottery , jobless etc.
Middle class means both not so busy and not so relaxed means middle class
For example , small busniessman and government agencies etc
Upper class means highly relaxed they sit on ac for doing their job wheares the low class people does their job on sunlight
Hence they are strong and healthy For example , big business man and industries holder etc
THANKS FOR LETTING ME TO HELP YOU