Question

The internal measures of a cuboidal room are 12 m × 8 m × 6 m. Find the total cost of whitewashing all four walls of a room, if the cost of white washing is Rs 5 per m.sq. ​

Answer 1

$\Large{\underbrace{\sf{\purple{Required\:Solution:}}}}$

Given thαt,

• The internαl meαsures of α cuboidαl room αre 12m×8cm×6cm.
• Cost of white wαshing is Rs.5m².

◾️We hαve to find the totαl cost of white wαshing αll four wαlls of the room.

______________

To do so,

We know thαt,

$\large\star{\boxed{\sf{\purple{ Lateral\:Surface\:Area_{(cuboid)} = 2(length+breadth)\times height}}}}$

• Substitute the vαlues αnd simplify.

$\implies{\sf{ 2(12m+8cm)\times 6cm}}$

$\implies{\sf{ 2(20m\times 6cm)}}$

$\implies{\sf{ 2(120m^{2})}}$

$\large\implies{\boxed{\sf{ 240m^{2}}}}$

Hence, the lαterαl surfαce αreα of the cuboidαl room is 240m².

Now,

Cost of white wαshing is Rs.5m².

• Multiply it with the Lαterαl surfαce αreα.

$\implies{\sf{ 240m^{2} \times 5}}$

$\large\implies{\boxed{\sf{\purple{ Rs. 1200}}}}$

Therefore, the cost of white wαshing of the four wαlls is Rs. 1200.

And we αre done! :D

__________________________

Answer 2

Question :-

⇒ The internal measures of a cuboidal room are 12 m × 8 m × 6 m. Find the total cost of whitewashing all four walls of a room, if the cost of white washing is Rs 5 per m.sq. ​

Given :-

⇒ Dimensions of Cuboidal room

  12 m

   8 m

   6 m

⇒ Cost of whitewashing per m² = Rs. 5

To Find :-

⇒ Cost of whitewashing all four walls

Solution :-

⇒ We need to find the  area of four walls

 → $\sf = 2h(l+b)\\\\\; = 2\times6\times (12 + 8 )\\\\= 2 \times 6 \times 20 \\\\= 240\;m^{2}$

⇒ Now , we need to find the cost of whitewashing them

$\sf Given\;that\;\\\\Cost\;of\;whitewashing\;is\;Rs.5\;per\;m^{2} \\\\So,\\\\Cost\;of\;whitewashing\;1\;m^{2}\;=\; Rs. 5 \\\\Cost\;of\;whitewashing\;240\;m^{2}\;=\; Rs.( 240\times5 )\\\\= Rs. 1200$