JEE Main 2019 Physics question
The density of a material in SI units is 128 kg m. In certain units in which the unit of length is 25 cm and the unit of mass is 50 g, the numerical value of density of the material is:
Answer: (A)
Solution
New unit = 0.05/(0.25) = 3.2 kg m; 128/3.2 = 40.