Directions: Four parts of the sentences given below have been underlined. Identify the part having an error. If no part has an error, mark (E).

Algebra is the (A) branch of mathematics concerned with operations on (B) sets of numbers or other (C) elements that are often represented as (D) symbol. (E) No error

The sentence says 'elements that are often represented as symbol'. Since 'elements' is plural, the noun should also be plural 'symbols'. Multiple elements are represented by multiple symbols, not a single symbol. The correct phrase should be 'represented as symbols'. This is a number agreement error between the noun and its modifier.