Important numerical of Newton's law of viscosity ( PU 2018)/fluid mechanics

Hello friends today I am going to teach you a important question of Newton's law of viscosity which was asked in bachelor in civil engineering in 2018 in third semester exam of fluid mechanics of purbanchal university. I Have solved this numerical step by step by giving a basic knowledge about unit conversion also and I have given a concept how apply Newton's law of viscosity shear stress formula to solve the question