Question

As part of a science lesson, pupils were asked to stretch a spring to extend its length by 50 per cent. The original length of the spring was 30 centimetres. What should be the length of the extended spring? Give your answer in centimetres.

Answer 1

Original length=30cm
50% of 30cm=15cm
Therefore,
New length= 30cm+15cm= 45cm

Hope I could help you with this:)

Answer 2

Concept

Percentages are defined as 100 specific parts or quantities. It has a denominator of 100  and is represented by the "%" symbol.The percentage has no dimensions.It means they are dimensionless numbers.

Given

We have given the percentage of length of the stretched spring which is 50 percent and the original length of the spring which is 30cm.

Find

We are asked to determine the length of the extended spring.

Solution

We need to find $50\%$ of $30cm$ .

When percentage sign is removed then, 100 comes in the denominator.

$\frac{50\times 30}{100} = 15 cm$

So we extended the spring by 15cm.

Hence, total length will be $=30+15$

                                             $=45cm$

Therefore, the length of the extended spring is 45cm .

#SPJ2