Question

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

11th - 12th Class

Maths

Solution

4.0 (1 ratings)

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} ]