Question

The length of a spring hanging from a stand
with nothing hanging off of it is 50 cm. When a
1 kg mass is hung from the spring the length
of the spring (when the mass is at rest) is 58
cm. The 1 kg mass is removed and a 5 kg
mass is hung on the spring instead. The 5 kg
mass is removed and is replaced by an
unknown mass. The time period of the
oscillation with the unknown mass is 25% that
of the time period when the 1 kg mass is
hanging from the spring. (e) What is the
unknown mass?​

Answer 1

I am not understanding the question...