The density of a material in SI units is 128 kg `m^(-3)`. 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 :

Explanation

`rho = m/V [rho] = [ ML^(-3) ]`
` 128 (1kg) (1m)^(-3) = x ( 100/1000 kg ) (25/100m)^(-3) rArr x = 128 xx 1000/100 xx 4^(-3) = (128 xx 10)/(64) = 20`