An 8N force stretches a spring to the 20cm mark on a metre rule.if the extension on the spring is 4cm,calculate the original length of the spring?

Answer 1

I think the answer is 16cm but I don't know how

Answer 2

if the spring is extended 4 cm to the 20 cm mark
... it must have started at the 16 cm mark

Answer 3

an 8n force stretches a spring to the 20cm on a metre rule. if the extension on the spring is 4 cm, calculate the original length of the spring