Question

please help me no ii) only​

Answer 1

3×12×10×8, 3×120×8, 3×960=2880

Answer 2

Required Solution:

Here, we have to find the volume and T.S.A of the cuboid having dimensions :

• Length = 20 cm
• Height = 12.5 cm
• Breadth = 15 cm

For T.S.A

$\sf { \leadsto{T.S.A}_{(Cuboid)} = 2(lb + bh + lh)}$

Inserting values:

$\sf { \leadsto{T.S.A}_{(Cuboid)} = 2[(20 \times 15) + (15 \times 12.5) + (20 \times 12.5)]}$

$\sf { \leadsto{T.S.A}_{(Cuboid)} = 2\bigg[(20 \times 15) + \bigg (15 \times \dfrac{125}{10}\bigg ) + \bigg(20 \times \dfrac{125}{10} \bigg)\bigg]}$

$\sf { \leadsto{T.S.A}_{(Cuboid)} = 2\bigg[(300) + \bigg (15 \times \dfrac{25}{2}\bigg ) + \bigg(20 \times \dfrac{25}{2} \bigg)\bigg]}$

$\sf { \leadsto{T.S.A}_{(Cuboid)} = 2\bigg[(300) + \bigg ( \dfrac{15 \times 25}{2}\bigg ) + \bigg(\dfrac{20 \times 25}{2} \bigg)\bigg]}$

$\sf { \leadsto{T.S.A}_{(Cuboid)} = 2\bigg[(300) + \bigg ( \dfrac{375}{2}\bigg ) + \bigg(\dfrac{500}{2} \bigg)\bigg]}$

$\sf { \leadsto{T.S.A}_{(Cuboid)} = 2\big[(300) + (187.5)+ 250\big]}$

$\sf { \leadsto{T.S.A}_{(Cuboid)} = 2\bigg[ \dfrac{7375}{10} \bigg]}$

$\sf { \leadsto{T.S.A}_{(Cuboid)} = \dfrac{7375}{5} }$

$\sf \red{ \leadsto{T.S.A}_{(Cuboid)} = 1475 \: {cm}^{2} }$

Hence, T.S.A of the cuboid is $\sf { 1475 \: {cm}^{2} }$

For volume :

We know that,

$\sf { \leadsto {Volume}_{(Cuboid)} = l \times b \times h}$

$\sf {\leadsto {Volume}_{(Cuboid)} = 20 \times 15 \times 12.5 \: {cm}^{3}}$

$\sf {\leadsto {Volume}_{(Cuboid)} = 300 \times \dfrac{125}{10} \: {cm}^{3}}$

$\sf {\leadsto {Volume}_{(Cuboid)} = 30 \times 125 \: {cm}^{3}}$

$\sf \red {\leadsto {Volume}_{(Cuboid)} = 3750 \: {cm}^{3}}$

Therefore volume of the cuboid is $\sf { 3750 \: {cm}^{3}}$

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Extra :

• Volume of cuboid = length × breadth × height

[ In cubic units ]

• L.S.A of cuboid = [2(l+b) × h]

[ In square units ]

• T.S.A of cuboid = 2 (lb + bh + lh)

[ In square units ]