If all of the six faces of a concrete block are rectangular, what is

a 6 sided block can be cube or rectangular block
#1
Each of the four lateral faces of the block has an area of 200 square inches.
a*b = 200
can be 10*20 ; but top and bottom surface area not know
dimensions of a,b,c not know insufficient
#2
The top of the block is square and has an area of 400 square inches
i.e a=b=20
but third side not know insufficient
from 1 &2
we can say that area of block ; 10*20*20 ; 4000
OPTION C

STRAIGHT to POINT:
1)Area of lateral alone >>insuff.
2)Area of Top n bottom alone>>> a2 =400>>a=20 >>insuff.

Now C: if a=side of square=one side of rectangle(L)=20>>>> other side of rectangle =200/20=10(given area of=200)

Now volume can be calculated

Therefore C

HOPE THIS HELPS

THANKS

BrentGMATPrepNow
I have a doubt. How can we say that the block is cuboid? It can be a cube.
As Square is a type of Rectangle and it is not mentioned anywhere in the question that the block is cuboid.
So, I think with that in mind we can say that Option B is correct.

Please correct me if I am wrong.

We know that the block is a cuboid, because we're told that all six faces are rectangular

Question: FInd volume of rectangular block?

Statement 1: Each of the four lateral faces of the block has an area of 200 square inches.
ie. \(L*H = B*H = 200\)
i.e. L = B

Case 1: L = B = 20 and H = 10 Volume = 4000
Case 2: L = B = 5 and H = 40 Volume = 1000

but we don't know the height and Length individual values

NOT SUFFICIENT

STatement 2: The top of the block is square and has an area of 400 square inches
Top = L*B = 400
i.e L = B = 20 (square so L=B)
H is unknown hence

NOT SUFFICIENT

COmbining the statements

Case 1: L = B = 20 and H = 10 Volume = 4000

SUFFICIENT

ANswer: Option C

Genoa2000 Please check the explanation and two cases in statement 1

Solution:

A new Og 2021 question

Let the dimensions of the concrete block be l, b, h for length, breadth and height respectively.

The volume of a cube = l.b.h

St(1):- Please let us know as and when you have queries in future.

The lateral faces are the four sides of the block.(You can imagine the four "walls" of a room)

Given, l h =200 and b h=200

=> l h=b h

=> l = b
However we do not know the third side to determine the value of the volume. (Insufficient)

St(2):- The top of the block is square and has an area of 400 square inches.

Let the dimension of the top square face be a units.

=> a^2 = 400

=> a = 20
Even though two of the dimensions are 20 each, we still do not know the third dimension needed for the volume.(Insufficient)

On combining both:-

l = b

l h = 200 and hence 20 * h =200 (20 is obtained as data from the second statement. You can also use b h=20)

Hence volume = lbh = 20*20*10 (Sufficient) option(C)

Hope this helps
Devmitra Sen(GMAT Quant Expert)

Answer: Option C

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