Refer to the following letter, number, symbol series and answer the question that follows.
(Left) K & 4 G ∞ S D 2 @ 6 C T % 7 R Z ∑ 3 5 N (Right)
How many such symbols are there in the given series each of which is immediately preceded by a letter and also immediately followed by a number?
1
Three
2
Two
3
One
4
None