What is combustion and combustible materials?

Combustion is a:

Select the correct alternative from the given options . Gas X to Combustible and not a supporter of combustion Gas to Combustible as well as a supporter of combustion . What could be X and Y ?

Boojho wants to separate the following materials as combustible and non-combustible. Can you help him? Charcoal, chalk, stone, iron rod, copper coin, straw, cardboard, glass, paper, candle, wood.

What is meant by rapid combustion ?