0
June 29, 2020, 9:56 p.m.
The length, breadth and height of a room are in the ratio 3:2:1. If the breadth and height are halved while the length is doubled, then the total area of the four walls of the room will

The length, breadth and height of a room are in the ratio 3:2:1. If the breadth and height are halved while the length is doubled, then the total area of the four walls of the room will

  1. remain the same
  2. decrease by 13.64%
  3. decrease by15%
  4. decrease by18.75%
  5. decrease by30%
quant
ration-and-proportion
Add Comment to Question
ANSWERS
0
June 30, 2020, 7:21 p.m.

Option 5: decrease by 30%

l:b:h = 3:2:1
We can say that l = 3k, b = 2k and h = k.

New length, breath and height will be 6k, k and k/2 respectively.

Old area of 4 walls will be 2h(l + b) = 2k(3k + 2k) = 2k(5k) = 10k2

new area will be 2(k/2)(6k + k) = k(7k) = 7k2 

we see 30% decrease in the area

Add Comment to Answer
In Order to answer this Question please login
Tags
quant
numbers
cat-2019
varc
rc
set-theory
time-speed-distance
quadratic
geometry
cat
Stats
Total Questions
57
Total Answers
32