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zorroprateek
- Newbie | Next Rank: 10 Posts
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What is the volume of a certain rectangular solid?
(1) Two adjacent faces of the solid have areas 15
and 24, respectively.
(2) Each of two opposite faces of the solid has
area 40.
Answer of the above question is C.
I know the first statement alone is not sufficient but statement two alone should be sufficient as EACH face area 40, that is l*b=40, b*h=40 and h*l=40.
But the explanation in OG for statement 2 is :-
If the edge lengths of the rectangular solid
are 5, 8, and x, where x is a positive real
number, then the rectangular solid will have
a pair of opposite faces of area 40, namely
the two faces that are 5 by 8. However, the
volume is (5)(8)(x), which will vary as x
varies; NOT sufficient.
i dont understand the above explanation as with edges 5,8 and x only two opposite faces will have area 40 and not EACH of the two opposite face, isn't it?
(1) Two adjacent faces of the solid have areas 15
and 24, respectively.
(2) Each of two opposite faces of the solid has
area 40.
Answer of the above question is C.
I know the first statement alone is not sufficient but statement two alone should be sufficient as EACH face area 40, that is l*b=40, b*h=40 and h*l=40.
But the explanation in OG for statement 2 is :-
If the edge lengths of the rectangular solid
are 5, 8, and x, where x is a positive real
number, then the rectangular solid will have
a pair of opposite faces of area 40, namely
the two faces that are 5 by 8. However, the
volume is (5)(8)(x), which will vary as x
varies; NOT sufficient.
i dont understand the above explanation as with edges 5,8 and x only two opposite faces will have area 40 and not EACH of the two opposite face, isn't it?
