If the side of a cube is increased by 20%, then what will be the percentage increase in the volume of cube?

Volume of cube = (edge)³ ∴ Single equivalent increase for 20% and 20% $=left(20+20+frac{20 imes 20}{100} ight) \%=44 \%$ Single equivalent increase for 44% and 20% $=left(44+20+frac{44 imes 20}{100} ight) \%$ = (64 + 8.8)% = 72.8% Alternate ; Fraction of 20% According to the question,

Increase in volume of cube $=frac{91}{125} imes 100=72.8 \%$