Question

The dining hall of a hotel is 12.5 m long, 9 m broad and 7 m high. It has two – doors 2.5m by 1.2m each and four windows 1.5 m by 1 m each. Find the cost of papering its wall at the rate of ₹ 3.50 per m2.​

Answer 1

Answer:

Given :-

• Length of dinning room = 12.5 m
• Breadth of dinning room = 9 m
• Height of Dinning room = 7 m
• Two doors of 2.5 m by 1.2 m
• Four windows of 1.5 m by 1 m
• Cost of 1 m = ₹ 3.50

To Find :-

Total Cost

Solution :-

As we know that

Area of wall = 2h(l + b)

Area of wall = 2 × 7(12.5 + 9)

Area of wall = 14(21.5)

Area of wall = 301 m²

Now,

Area of two doors = 2( l × b)

Area of two doors = 2(2.5 × 1.2)

Area of two doors = 2(3)

Area of two doors = 6 m²

Now,

Area of 4 windows = 4(l × b)

Area of 4 windows = 4( 1.5 × 1)

Area of 4 windows = 4(1.5)

Area of 4 windows = 6 m²

Now,

Total area of walls = Area of wall - Area of two doors - Area of 4 windows

Total area of walls = 301 - 6 - 6

Total area = 289 m²

Now,

Total Cost = 289 × 3.5

Total Cost = ₹1011.5

Answer 2

Given :

The dining hall of a hotel is 12.5 m long, 9 m broad and 7 m high. It has two – doors 2.5m by 1.2m each and four windows 1.5 m by 1 m each.

To find :

The cost of papering its wall at the rate of ₹ 3.50 per m²

Solution :

• The dining hall of a hotel is 12.5 m long, 9 m broad and 7 m high.

★ Length of a dining hall (l) = 12.5 m

★ Breadth of a dining hall (b) = 9m

★ Height of a dining hall (h) = 7m

Lateral surface area of dining hall

→ 2(l + b)h

→ 2(12.5 + 9)7

→ 2 × 21.5 × 7

→ 14 × 21.5

→ 301 m²

________________________________

• Dining hall has two – doors 2.5m by 1.2m each

★ Length of a door = 2.5 m

★ Breadth of a door = 1.2 m

Area of a door = Area of rectangle

→ length × breadth

→ 2.5 × 1.2

→ 3 m²

•°• Area of two doors = 3 × 2 = 6m²

________________________________

• Dining hall has four windows 1.5 m by 1 m each.

★ Length of a window = 1.5 m

★ Breadth of a window = 1 m

Area of a window = Area of rectangle

→ Length × breadth

→ 1.5 × 1

→ 1.5 m²

•°• Area of four window = 4 × 1.5 = 6 m²

________________________________

Area of papering dining hall wall

★ Lateral surface area of hall - Area of two doors - Area of four windows

→ 301 - 6 - 6

→ 301 - 12

→ 289 m²

________________________________

• Rate of papering the wall = ₹ 3.50

Cost of papering the wall

→ 289 × 3.50

→ Rs.1011.5

________________________________