Answer:
In first case vibrational frequency will be 246 Hz and 254 Hz
In second case vibrational frequency will be 264 Hz and 246 Hz
Step-by-step explanation:
We have given a guitar produces 4 beats per second when sounded with 250 Hz and produce 9 beats per second when sounded with 255 Hz
Expression of beat frequency is
Here
is vibrational frequency
So
For second case