Interference : GPS Transmission

[cupcake]

i hope so..

please somebody enlighten me..

though, i guessed nothing wrong about the answer 27

 

[cupcake]

somebody..
please advise me how to part A...
i don't know why my answer is wrong.. :( :(

 

[skeptic2]

In my opinion 27 was the correct answer. I only started looking at other possibilities after you said it was wrong. I wish you would post the correct answer when you find out.