Question

the length and breadth of a room are into the ratio 4 : 3 and its height is 5.5m.the cost of decorating its wall at Rs6.60 per sq.month is Rs5080.Find the length and breadth of the room​

Answer 1

Correct Question :

The length and breadth of a room are in the ratio of 4 : 3 and it's height is 5.5 m. The cost of decorating it's wall at Rs 6.60 per sq. of month is Rs. 5080. Find the length and breadth of the room.

$\huge\underline\green {\tt Solution:}$

➡ Let common favor of lengthand breadth be x.

So, length = 4x and breadth = 3x

Also,

height = 5.5 m

•°• 1 m = 100 cm

so, 5.5 × 100 = 550 cm

Room is in cuboidal shape.

Now,

The cost of decorating it's wall = Rs 5080

➡ To find total cost :

Total cost = Area for the decoration × given rate

5080 = 2h ( l + b ) × 6.60

➡ 5080 = 2 × 550 ( 4x + 3x ) × 6.60

➡ 5080 = 110 ( 7x ) × 6.60

➡ 5080 = 770x × 6.60

➡ x = $\dfrac {5080}{770×6.60}$

•°• x = 0.99

x = 1 ( approx value )

Now,

Length = 4 × 1 = 4 cm

Breadth = 3 × 1 = 3 cm