Question

If two cubes of volume 64cm cube are joined end to end,then the surface area of the resulting cuboid is
a). 128cm square
b). 162cm square
c). 160cm square
d). 64cm square​

Answer 1

Answer:

32 cm sq.

Step-by-step explanation:

side of cube = 4 cm ( 4*4*4=64)

area of cuboid =l *b = 8 * 4

= 32cm square

Answer 2

Answer :

➥ Surface area of the cuboid = 160 cm²

Given :

➤ Volume id two cubes = 64 cm³

➤ Two cubes are joined end to end

To Find :

➤ Surface area of the cuboid = ?

Solution :

Volume of cube = 64 cm³

$\tt{:\implies {a}^{3} = 64}$

$\tt{:\implies a = \sqrt[3]{64} }$

$\tt{:\implies a = \sqrt[3]{4 \times 4 \times 4} }$

$\bf{:\implies \underline{ \: \: \underline{ \green{ \: \: a = 4 \: cm \: \: }} \: \: }}$

So ,

Length of cuboid (l) = 4 + 4 = 8 cm

Breath of cuboid (b) = 4 cm

Height of cuboid (h) = 4 cm

Now ,

Surface area of cuboid

$\tt{: \implies 2(lb + bh + hl)}$

$\tt{: \implies 2(8 \times 4 + 4 \times 4 + 4 \times 8)}$

$\tt{: \implies 2(32 + 16 + 32)}$

$\tt{: \implies 2 \times 80}$

$\bf{: \implies \underline{ \: \: \underline{ \purple{ \: \: 160 \: {cm}^{2} \: \:}} \: \: } }$

Hence, the surface area of the cuboid is 160 cm².