The length, breadth and height of a room are in ratio 3:2:1. If breadth and height are halved while the length is doubled, then the total area of the four walls of the room will
A. remain the same
B. decrease by 13.64%
C. decrease by 15%
D. decrease by 18.75%
E. decrease by 30%
Answer: Option E
Solution(By Examveda Team)
Let length, breadth and height of the room be 3, 2, 1 unit respectively. Area of walls = 2(l + b) × h = 2(3 + 2) × 1 = 10 sq. unit. Now, length, breadth and height of room will become 6, 1 and $$\frac{1}{2}$$ respectively. Now, area of walls = $$2\left( {6 + 1} \right) \times \frac{1}{2}$$ = 7 sq. unit. % decrease in the area of walls = $$\left( {10 - 7} \right) \times \frac{{100}}{{10}}$$ = 30%Join The Discussion
Comments ( 2 )
Related Questions on Percentage
A. $$\frac{1}{4}$$
B. $$\frac{1}{3}$$
C. $$\frac{1}{2}$$
D. $$\frac{2}{3}$$
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