A large wooden box, open at the top, needs to be lined with fabric on its inner floor and inner four side walls. The inner dimensions of the box are 2.5 m length, 1.8 m wide, and 1.2 m high. If the fabric comes in square pieces of side 50 cm, and 15% extra fabric is needed for cuts and overlaps, how many approximate fabric pieces should be purchased?
Show answer & explanation
Correct answer: C
Explanation
The correct answer is option 3 i.e. 69
Floor = 2.5 × 1.8 = 4.5
Walls = 2 × 2.5 × 1.2 + 2 × 1.8 × 1.2
Walls = 6 + 4.32 = 10.32
Total area = 4.5 + 10.32 = 14.82
With 15% extra = 14.82 × 115/100 = 17.043
One piece area = 0.5 × 0.5 = 0.25
Pieces = 17.043 / 0.25 = 68.172
Required pieces = 69