Consider the following

(A) 0.0025

(B) 500.0

(C) 2.0034

Number of significant figures in $A, B$ and $C$ respectively, are

1.84 g of a mixture of $\mathrm{CaCO}_3$ and $\mathrm{MgCO}_3$ is strongly heated to get a residue of 0.96 g . The percentage of $\mathrm{CaCO}_3$ in the mixture is

209 g of an element reacts with chlorine to form 315.5 g of its chloride. What is the weight (in g ) of oxygen that reacts with 418 g of same element ?

$$ (\mathrm{Cl}=35.5 \mathrm{u} ; \mathrm{O}=16 \mathrm{u}) $$