Analyzing the Number and Symbol Series

The question requires us to analyze the given series: $\% 9 \% 2 7 5 & \$ \* 5 \textcopyright 6 1 1 \* \texteuro 4 \# 1 7 3 \@$. Our goal is to count how many symbols satisfy two specific conditions. The analysis must proceed strictly from left to right.

The conditions for a symbol to be counted are:

• Condition 1: The symbol must be immediately preceded by a number (i.e., 0-9).
• Condition 2: The symbol must be immediately followed by another symbol.

Step-by-Step Symbol Check in the Series

We will examine each symbol in the series to see if it meets both conditions:

• The first $\%$: It is preceded by $\%$ (a symbol), not a number. Fails Condition 1.
• The second $\%$: It is preceded by $9$ (a number), satisfying Condition 1. However, it is followed by $2$ (a number), not a symbol. Fails Condition 2.
• The symbol $&$: It is preceded by $5$ (a number), satisfying Condition 1. It is followed by $\$ (a symbol), satisfying Condition 2. This symbol meets both conditions. (Count = 1)
• The symbol $\$: It is preceded by $&$ (a symbol), not a number. Fails Condition 1.
• The first $\*$: It is preceded by $\$ (a symbol), not a number. Fails Condition 1.
• The symbol $\textcopyright$: It is preceded by $5$ (a number), satisfying Condition 1. However, it is followed by $6$ (a number), not a symbol. Fails Condition 2.
• The second $\*$: It is preceded by $1$ (a number), satisfying Condition 1. It is followed by $\texteuro$ (a symbol), satisfying Condition 2. This symbol meets both conditions. (Count = 2)
• The symbol $\#$: It is preceded by $4$ (a number), satisfying Condition 1. However, it is followed by $1$ (a number), not a symbol. Fails Condition 2.
• The symbol $\@$: It is preceded by $3$ (a number), satisfying Condition 1. However, it is at the very end of the series, so it is not followed by any character, let alone a symbol. Fails Condition 2.

Final Conclusion on the Symbol Count

After meticulously checking every symbol in the sequence against the specified criteria, we found exactly two symbols that fulfill both requirements:

• The symbol $&$, because it's between the number $5$ and the symbol $\$.
• The symbol $\*$, because it's between the number $1$ and the symbol $\texteuro$.

Therefore, the total count of symbols meeting both conditions is 2.