Question

20. Length, breadth and height of a cuboid are 3 cm, 2cm and 1cm respectively find
a)The total surface are
b) Volume
c)Lateral surface area
d) Find the volume when length, breadth and height are doubled
e) Ratio of their volumes in question b&d
​

Answer 1

Answer:

Given:-

l=3cm

b=2cm

h=1cm

Formula used:-

TSA of cuboid=2(lb+bh+lh)

Volume of cuboid=l×b×h

LSA of cuboid=2h(l+b)

Solution A:-

Since,TSA of cuboid=2(lb+bh+lh)

TSA=2(3cm(2cm)+2cm(1cm)+3cm(1cm))

$TSA=2(6 {cm}^{2} + 2 {cm}^{2} + 3 {cm}^{2} )$

$TSA=2(11 {cm}^{2} )$

$TSA=22 {cm}^{2}$

Solution B:-

Since,Volume of cuboid=l×b×h

Volume=3cm×2cm×1 cm

$= {6cm}^{3}$

Solution C:-

Since,LSA of cuboid=2h(l+b)

LSA=2(1cm)(3cm+2cm)

=2cm(5cm)

$= 10 {cm}^{2}$

Solution D:-

If length, breath and height are doubled:-

l=2(3cm)

=6cm

b=2(2cm)

=4cm

h=2(1cm)

=2cm

Since,Volume=l×b×h

Volume=6cm×4cm×2cm

$Volume=48 {cm}^{3}$

Solution E:-

$Ratio \: \: of \: \: volumes \: \: in \: \: question \: \: b \: \: and \: \: d= \frac{6}{48}$

$= \frac{1}{8}$

=1:8