(10) In a shelf there are 5 books of thickness 20 mm and 5 papers of thickness 0.016mm. What is the total thickness of the shelf?
Answers
Answer:
Given :
Length , Breadth and Height of brick are in the ratio 1:2:3 .
Total Surface area of brick is 792 m² .
To Find :
Volume of brick .
Solution :
First we'll find the length , breadth and height :
\longmapsto\tt{Let\:Length\:be=1x}⟼LetLengthbe=1x
\longmapsto\tt{Let\:Breadth\:be=2x}⟼LetBreadthbe=2x
\longmapsto\tt{Let\:Height\:be=3x}⟼LetHeightbe=3x
Using Formula :
\longmapsto\tt\boxed{T.S.A\:of\:Cuboid=2(lb+bh+hl)}⟼
T.S.AofCuboid=2(lb+bh+hl)
Putting Values :
\longmapsto\tt{792=2(1x\times{2x}+2x\times{3x}+3x\times{1x})}⟼792=2(1x×2x+2x×3x+3x×1x)
\longmapsto\tt{792=2({2x}^{2}+{6x}^{2}+{3x}^{2})}⟼792=2(2x
2
+6x
2
+3x
2
)
\longmapsto\tt{792=2({11x}^{2})}⟼792=2(11x
2
)
\longmapsto\tt{792=22{x}^{2}}⟼792=22x
2
\longmapsto\tt{\cancel\dfrac{792}{22}={x}^{2}}⟼
22
792
=x
2
\longmapsto\tt{\sqrt{36}=x}⟼
36
=x
\longmapsto\tt\bf{6=x}⟼6=x
Value of x is 6 .
Therefore :
\longmapsto\tt{Length\:of\:brick=1(6)}⟼Lengthofbrick=1(6)
\longmapsto\tt\bf{6\:m}⟼6m
\longmapsto\tt{Breadth\:of\:brick=2(6)}⟼Breadthofbrick=2(6)
\longmapsto\tt\bf{12\:m}⟼12m
\longmapsto\tt{Height\:of\:brick=3(6)}⟼Heightofbrick=3(6)
\longmapsto\tt\bf{18\:m}⟼18m
Now ,
For Volume :
Using Formula :
\longmapsto\tt\boxed{Volume\:of\:Cuboid=l\times{b}\times{h}}⟼
VolumeofCuboid=l×b×h
Putting Values :
\longmapsto\tt{6\times{12}\times{18}}⟼6×12×18
\longmapsto\tt\bf{1296\:{m}^{3}}⟼1296m
3
So , The Volume of Cuboid is 1296 m³ .
Option A) 1296 m³ is Correct