Answer:
The appositive in the sentence is "a flashy yellow ten-speed"
The appositive is essential because it describes Justin's bike
The purpose of the appositive is to clarify Justin's bike
Step-by-step explanation:
Apposition has to do with construction of grammar in which two elements are placed side by side to identify or clarify the other in a different way.
The word 'apposition' is derived from the Latin words 'ad' which means near and 'positio' which means placement.
From the sentence,
Justin's bike, a flashy yellow ten-speed, is faster than mine
the appositive is "a flashy yellow ten-speed'' which describes Justin' s bike.