What is the total surface area of rectangular solid R ?

Its E.

from statement 1:

surface area of one face = l*b = 48,
then we can have the following combination of l*b.

1*48
2*24
3*16
4*12
6*8... and may be few more.. we can have different values of surface area depending on the value of third side.

from statement 2:

Alone one side is not enough.

From from statement 1 and from statement 2:

we can still have two cases : where l or b or itself is 3, then we still don't have the third side.

What is the total surface area of rectange solid R?

1) The surface area of one of the faces of R is 48
2) The length of one of the edges of R is 3

My Ans - Both together also not sufficient.

Let us take opt 1)
there are two shapes in a rectangular solid
a. Squre shape - 2 nos
b. rectangular shape - 4 nos
we cant say for which shape the above given area belongs to..
So it is not sufficiant

Let us take opt 2)
Since length and breadth are different for rectangular solid. we cant deduce the area.
So it is not sufficient independently

let us take both together.
The above given area may be for Square or rectangular.
If it is square , it's side may be 4sqrt(3) and length may be 3. we can deduce area - 179.136
if it is rectangular , l=3,b=16.So area = 210.
So both together also not sufficient

I have one question to above explanation,
since it is Solid triangular, we need to know the heigh of this solid right in order to find total surface area..?!

Just like when you have to compute the surface area of cylinder

thanks in advance

Solid rectangular just implies that its a 3D object and not a plain rect drawn on paper but its area can be calulated just like any other plain rectangle.

For rectangular surface are, we simply need the 2 sides - length and breadth.
Surface area = area of 2 square faces + 4 rectangular faces.
There is nothing like height of a rectangle, you can put it on either face and the standing side becomes the height

In cyliner we have 2 circular faces + a rolled over part. To get the area od this rolled part we need the height.

OA/OE please? I'm pretty confident the answer is straight E

Please confirm
Cheers!
J

What is the total surface area of rectangular solid R ?

(1) The surface area of one of the faces of R is 48. Clearly insufficient.

(2) The length of one of the edges is 3. Clearly insufficient.

(1)+(2) The dimensions can be 3 to 16 to {any} or x to y to 3, (where x*y=48). Not sufficient. Also, notice that the edge of length 3 could be one of the sides of the face whose area is 48 as well as one of the sides of one of the other faces.

Answer: E.
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I am little bit skeptical whether rectangle can be square. Guys, help me, please?

What do you mean by Rectangle can be a square. There is nothing of that sort given in the question nor can we deduce that.
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I was just confused because Inaranayan wrote above about it.

The surface area of a rectangular solid is found out by adding the area of each of the six faces. For finding out the surface area we need to know the width (w), height (h), and length (l) (Note that in case of a cube w,l,h are equal). The surface area is given as 2(w*h+h*l+w*l)

In the first statement we have that the area of one of the faces is 48. Then the area opposite to this face will also have an area of 48. But this gives us the area of only 2 of the faces (or one pair of equal faces, where as a rectangular solid has 3 pairs of equal faces) and we have no clue about the other 4 faces. So this statement is not sufficient.

The second statement says that the length of one of the edges is 3. This could be the value of w,h,l. But to find out the value of the surface area we need all the 3 values hence this statement is also insufficient.

Now, even when we combine the 2 statements we see that though we know the surface area of one of the faces and one of the lengths, we still dont know whether the length is the length of w,h,l . With the help of the given information we can find the length of one more length as 48 =3 * w or 3*h or 3*l. We still wont get the value of all the length and hence wont be able to find out the surface area. Hence the answer is E.

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