Example 1 - A door-frame of dimensions 3 m x 2 m is fixed on the wall

Example 1 - Chapter 11 Class 7 Perimeter and Area - Part 2
Example 1 - Chapter 11 Class 7 Perimeter and Area - Part 3


Transcript

Question 1 A door-frame of dimensions 3 m × 2 m is fixed on the wall of dimension 10 m × 10 m. Find the total labour charges for painting the wall if the labour charges for painting 1 m2 of the wall is Rs 2.50. Area to be painted = Area of square wall − Area of rectangular door frame Wall Side of wall = a = 10 m Area of wall = a × a = 10 × 10 = 100 m2 Door Frame Length = l = 3 m Breadth = b = 2 m Area of door frame = l × b = 3 × 2 = 6 m2 Therefore, Area to be painted = 100 − 6 = 94 m2 Now, Labour charge for painting 1m2 of wall = Rs 2.50 Labour charge for painting 94m2 of wall = Rs 2.50 × 94 = Rs 25/10 × 94 = Rs 5/2 × 94 = Rs 5 × 47 = Rs 235 ∴ Labour will charge Rs 235

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Davneet Singh

Davneet Singh has done his B.Tech from Indian Institute of Technology, Kanpur. He has been teaching from the past 14 years. He provides courses for Maths, Science, Social Science, Physics, Chemistry, Computer Science at Teachoo.