A) 72 Hz
B) 288 Hz
C) 84 Hz
D) 87 Hz
E) 144 Hz
Correct Answer: C
Solution :
If n is the frequency of last fork then frequency of first fork be\[2n\]. So, \[2n-(25-1)\times 3=n\] \[\Rightarrow \] \[n=72\,Hz\] 21st fork frequency \[=144-(21-1)(3)\] \[=84\text{ }Hz\]You need to login to perform this action.
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