Concept:
In Simple Harmonic Motion (SHM), if a particle starts from the extreme position, its displacement at time \(t\) is:
\[
x=A\cos \omega t
\]
where
\[
\omega=\frac{2\pi}{T}
\]
The distance travelled from the extreme position is:
\[
A-x
\]
Step 1: Find angular frequency.
\[
\omega=\frac{2\pi}{T}
\]
Given:
\[
t=\frac{T}{12}
\]
Therefore,
\[
\omega t=\frac{2\pi}{T}\times \frac{T}{12}
=\frac{\pi}{6}
\]
Step 2: Find displacement after \(\frac{T}{12}\) time.
Since motion starts from extreme position,
\[
x=A\cos\frac{\pi}{6}
\]
\[
x=A\left(\frac{\sqrt3}{2}\right)
\]
\[
x=\frac{\sqrt3 A}{2}
\]
Step 3: Compute distance travelled.
Initially particle is at:
\[
x=A
\]
Final position:
\[
x=\frac{\sqrt3A}{2}
\]
Hence distance travelled:
\[
A-\frac{\sqrt3A}{2}
\]
\[
=\frac{2A-\sqrt3A}{2}
\]
\[
=\frac{A(2-\sqrt3)}{2}
\]
Hence the required answer is:
\[
\boxed{\frac{A(2-\sqrt3)}{2}}
\]