Suppose 2 J of work is needed to stretch a spring from its natural length of 30 cm to a length of 42 cm.Then how far beyond its natural length will a force of 30 N keep the spring stretched?

Question

$\begin{array}{1 1}\large\frac{27}{10}\\\large\frac{29}{10}\\27\\\large\frac{17}{10}\end{array} $