Given that one root of the equation $$\,{x^3} - 10{x^2} + 31x - 30 = 0\,\,$$ is $$5$$ then other roots are

The presence of hardness in excess of permissible limit causes

The alkalinity and the hardness of a water sample are 250 mg/L and 350 mg/L as $$CaCo_3$$, respectively. The water has

The plan of a map was photo copied to a reduced size such that a line originally 100mm, measures 90mm. The original scale of the plan was 1:1000. The revised scale is