Concept:
For independent events, the probability that exactly one event occurs is the sum of the probabilities of the following mutually exclusive cases:
\[
A\cap B^c\cap C^c,
\]
\[
A^c\cap B\cap C^c,
\]
\[
A^c\cap B^c\cap C.
\]
Also,
\[
P(A^c)=1-P(A).
\]
Step 1: Find the probabilities of the complementary events.
\[
P(A^c)=1-\frac34=\frac14,
\]
\[
P(B^c)=1-\frac56=\frac16,
\]
\[
P(C^c)=1-\frac23=\frac13.
\]
Step 2: Find the probability that only \(A\) occurs.
Since the events are independent,
\[
P(A\cap B^c\cap C^c)
=
P(A)P(B^c)P(C^c).
\]
\[
=
\frac34\cdot\frac16\cdot\frac13.
\]
\[
=
\frac1{24}.
\]
Step 3: Find the probability that only \(B\) occurs.
\[
P(A^c\cap B\cap C^c)
=
P(A^c)P(B)P(C^c).
\]
\[
=
\frac14\cdot\frac56\cdot\frac13.
\]
\[
=
\frac5{72}.
\]
Step 4: Find the probability that only \(C\) occurs.
\[
P(A^c\cap B^c\cap C)
=
P(A^c)P(B^c)P(C).
\]
\[
=
\frac14\cdot\frac16\cdot\frac23.
\]
\[
=
\frac1{36}.
\]
Step 5: Add the three mutually exclusive cases.
\[
P(\text{exactly one event occurs})
=
\frac1{24}
+
\frac5{72}
+
\frac1{36}.
\]
Taking LCM \(=72\),
\[
=
\frac3{72}
+
\frac5{72}
+
\frac2{72}.
\]
\[
=
\frac{10}{72}.
\]
\[
=
\frac5{36}.
\]
Step 6: Write the final answer.
\[
\boxed{\frac5{36}}
\]