Please someone should help me with this.

Question

An elastic material has a length of 36cm when a load of 40N is hung on it and a length of 45cm when a load of 60N is hung on it. The original length of the string is ?

Answer 1

using youngs modules from hookes law that is strain. e/l, where e=length of material - initial length/original length 45-36=l l=9