The length of a cuboid-shaped box is increased by 10%, its breadth by 20%, and its height is decreased by 25%. What happens to its volume?

It decreases by 1%Correct answerYour answerIt stays the sameCorrect answerYour answerIt increases by 1%Correct answerYour answerIt increases by 5%Correct answerYour answer

Show the answer and explanation

CorrectNot quiteAnswer A

Correct answer: A

Volume multiplies by $1.1 \times 1.2 \times 0.75$ .
$1.1 \times 1.2 = 1.32$ , and $1.32 \times 0.75 = 0.99$ .
So the volume decreases by 1%.

Worth noting

Adding the changes $(10 + 20 - 25 = 5)$ gives "increases by 5%", the trap. Multiply the factors instead.

Concept: Volume change when three dimensions change
Typical timeTypical: 90 s
Your timeYours: —

The rule this testsSuccessive percentage change

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Ten questions from Percentages, at your own pace.

The length of a cuboid-shaped box is increased by 10%, its breadth by 20%, and its height is decreased by 25%. What happens to its volume?

Explanation