3. (3 points) Define a new operation: $a \& b=(a+1) \div b$, find the value of: $2 \&(3 \& 4)$

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3. (3 points) Define a new operation: $a \& b=(a+1) \div b$, find: $2 \&(3 \& 4)$, the value is $\qquad$ 3 .

【Solution】Solution: $2 \&(3 \& 4)$,
$$
\begin{array}{l}
=(2+1) \div[(3+1) \div 4], \\
=3 \div 1, \\
=3
\end{array}
$$

Therefore, the answer is: 3 .