Question

the length, breadth and height of a room are 5m 4m and 3m respectively.find the cost of white washing the Wall of the room and the ceiling at the rate of ₹7.50 per metre square​

Answer 1

Given :

• Length of Room = 5m
• Breadth of Room = 4m
• Height of Room = 3m

To Find :

• Cost of white washing at the rate of Rs.7.50 per m²..

Solution :

$\longmapsto\tt{Length(l)=5m}$

$\longmapsto\tt{Breadth(b)=4m}$

$\longmapsto\tt{Height(h)=3m}$

Using Formula :

$\boxed{S.A\:of\:Cuboid=2(lb+bh+hl)-lb}$

Putting Values :

$\longmapsto\tt{2(5\times{4}+4\times{3}+3\times{5})-(5\times{4})}$

$\longmapsto\tt{2(20+12+15)-(20)}$

$\longmapsto\tt{2(47)-20}$

$\longmapsto\tt{94-20}$

$\longmapsto\tt\bold{74{m}^{2}}$

Now :

Cost of Ceiling at Rs7.50 per m² :-

$\longmapsto\tt{74\times{7.50}}$

$\longmapsto\tt\bold{Rs.555}$

Answer 2

_____________________

Question :-

• the length, breadth and height of a room are 5m 4m and 3m respectively.find the cost of white washing the Wall of the room and the ceiling at the rate of ₹7.50 per metre square

_____________________

Given :-

• l = 5m
• b = 4m
• h = 3m
• the ceiling at the rate of ₹7.50 per metre square

_____________________

to find :-

• .find the cost of white washing the Wall of the room .

_____________________

solution :-

= 2 × ( l + b ) × h + l × b

= 2 × ( 5 + 4 ) × 3 +5 × 4

= 2 × 9 × 3 + 20

= 54 + 20

= 74

cost of white washing 1m = rs 7.5

Hence cost of 74m = 7.5 × 74 = rs555