The length and the breadth of a cuboid are increased by 10% each, whereas the height is reduced by 10%. By how much did the volume change?

8.9% increase

We know that,

volume of cuboid = length × breadth × height

We have,

Length and Breadth increased by = 10%

Height is decreased by = 10%

Let the length, breadth and height = 100

The volume of cuboid = 100 × 100 × 100 = 1000000

After all the increment and decrement in the sides,

The volume of cuboid = 110 × 110 × 90 = 1089000

Change in volume = 1089000 – 1000000 = 89000

Percentage change in  volume = 89000 × \(\frac{100}{1000000}\) = 8.9%