Question 752845
A cube has all sides of equal lengths.

Ratio (Small:Big) = 2:5

Length of small = 5cm
Length of big = (let's say) xcm

2:5=5:x
{{{(2/5)=(5/x)}}}
Cross Multiply
{{{2x=25}}}
{{{x=(25/2)}}}

Therefore, length of big cube on each edge = {{{(25/2)cm}}}

But volume of cube = l^3
Volume of Big cube = {{{(25/2)^3}}} => {{{15625/8}}} => {{{1953.125}}}

Therefore, volume of larger cube = {{{1953cm^3}}} to nearest whole number of cubic units.