Ex 13.1, 2 - The length, breadth and height of a room are - Ex 13.1

Ex 13.1, 2 - Chapter 13 Class 9 Surface Areas and Volumes - Part 2

Go Ad-free

Transcript

Question 2 The length, breadth and height of a room are 5 m, 4 m and 3 m respectively. Find the cost of white washing the walls of the room and the ceiling at the rate of Rs 7.50 per m2. Length (l) of room = 5 m Breadth (b) of room = 4 m Height (h) of room = 3 m We whitewash the four walls and the ceiling of the room Area to be white-washed = Area of cuboid – Area of base = 2(lb + bh + lh) – lb = 2(lb) + 2(bh) + 2(lh) – lb = lb + 2(bh) + 2(lh) = [(5 × 4) + (2 × 4 × 3) + (2 × 5 × 3)] m2 = (20 + 24 + 30) m2 = 74 m2 Cost of white-washing per m2 area = Rs 7.50 Cost of white-washing 74 m2 area = Rs (74 × 7.50)

Davneet Singh's photo - Co-founder, Teachoo

Made by

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.