Question

28. (1) Let side of a cube be 'a Surface area of the cube ( =6 a^{2} ) ( therefore quad 6 a^{2}=486 )
[
begin{array}{l}
Rightarrow quad a^{2}=frac{486}{6}=81
a=sqrt{81}=9
end{array}
]
( therefore ) Volume of the cube
[
=(operatorname{side})^{3}=9^{3}=729 mathrm{m}^{3}
]

# 28. The surface area of a cube is 486 sq m, then its volume is (1) 729 m (2) 781 m (3) 625 m3 (4) 879 m

Solution