Question

A photo frame of length 28 cm. and breadth 11 cm. has done decoration of 3 cm. along inside shown in the figure. Find the total area of decoration. If the cost of decoration is ₹ 2 per Sq.cm., find total cost of decoration.

Answer 1

Given the length of frame ABCD = 28 cm 

Breadth = 11 cm 

Area of frame ABCD = l × b 

= 28 × 11 = 308 sq.cm 

Width of the decoration part = 3 cm 

Decoration is tying inside the frame. 

So, length of EFGH = l – 2 × width 

= 28 – 2 × 3 

= 28 – 6 = 22 cm 

Breadth = b – 2 × width 

= 11 – 2 × 3 

= 11 – 6 = 5 cm

Area of frame EFGH = l × b 

= 22 × 5 = 110 sq.cm 

Area of the decoration

= 308 – 110 = 198 sq.cm 

Cost of decoration per sq.cm = ₹ 2 

Cost of decoration per 198 sq.cm = 198 × 2 

∴ Total cost of decoration = ₹ 396.

Answer 2

Dimension of Photo Frame:

Length : 28 cm

Breadth : 11 cm

Total Area of photo frame :- L x B

                                               = 28 x 11 cm²

                                               = 308 cm²

Since, Decoration has done along inside of 3cm

 

Then, Dimension of frame without decoration :

Length : (28 - 2x3)  cm = 22cm

Breadth: (11-2x3) cm = 5cm

Area of Frame without decoration = 22x5 cm²

                                                           = 110 cm²

Total Area of Decoration = (308-110) cm²

                                          = 198cm²

Cost of Decoration = Rs. 2/cm²

Total cost of decoration = Rs. (2x 198) 

                                           = Rs. 396