The total percentage change in the volume of a cuboid if its length and breadth are decreased by 15% and 25%, respectively, while its height is increased by 60% is:
Show answer & explanation
Correct answer: C
Explanation
The correct answer is option 3 i.e. 2% increase.
Let the length, breadth and height of the given cuboid be l, b and h respectively.
Volume of rectangle = lbh
According to the given question,
New length = 85% of l = 0.85l
New breadth = 75% of b = 0.75b
New height = 160% of h = 1.6h
Now, new volume = 0.85l × 0.75b × 1.6h
⇒ 1.02lbh
Change in volume = Increase in the volume = New volume - old volume
⇒ 1.02lbh - lbh = 0.02lbh
Percentage change = = 2%
Hence the total percentage change in the volume of a cuboid is 2% increase.