Forget conventional ways of solving math questions. In DS, Variable approach is the easiest and quickest way to find the answer without actually solving the problem. Remember equal number of variables and independent equations ensures a solution.

What is the surface area of a certain rectangle solid?

1) The volume of the solid is 96

2) The one face’s area of the solid is 12

There are 3 variables(length, width, height) for a rectangular solid, which should match with the number of equations. So you need 3 equations. For 1) 1 equation, for 2) 1 equation, which makes E the answer.

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