Two springs P and Q having stiffness constants k₁ and k₂ (< k₁), respectively are stretched equally. Then : 

More work is done on P

Since : \(k_1 > k_2\)

Therefore, P will develop greater restoring force than Q. So the applied force on P will be more than the applied force on Q. Extension is same in both the cases.

so, more work is done on P.