Maths Olympiad Prep

Library / /116 of 213

, 2013

Geometry Difficulty 1.5 Junior Find the answer Canada

A cube has a surface area of 54 cm2^{2}. The volume of the cube, in cm3^{3}, is

Pick one

Solution

Substituting x=4x=4 into 3x+2y3x+2y we get, 3(4)+2y=12+2y3(4)+2y=12+2y.

Since this expression 12+2y12+2y is equal to 30, then 2y2y must equal 301230-12 or 18.
If 2y=182y=18, then yy is 18÷218\div2 or 9.

Want a route through all this instead of an archive? The track puts 2,444 problems in a working order, from Junior Challenge level to the IMO shortlist.

Source: CEMC, University of Waterloo, licensed CC-BY-NC-4.0. Statement reproduced verbatim; metadata (topic, difficulty) added by this project.