Resonance frequencies question (first and second resonance frequencies)

[supernova1203]

Trying to figure out how to go about solving this question, using these forumlas i tried to solve it but i didnt get the right answers

for frequency 1 i went with

f1=v/2L

for frequency 2 i went with

f2=v/L


any ideas on how to solve this?

 

[AlephZero]

The question says the whistle is closed at one end.

You had the right idea about how to answer the question, but you used the wrong formulas.