Background Paragraph: A large log placed in a fire will burn relatively slowly. If the same mass of wood were added to the fire in the form of small twigs, they would burn much more quickly. This is because the twigs provide a greater surface area than the log does. An increase in the surface area of a reactant increases the rate of a reaction. Surface area is larger when a given amount of a solid is present as smaller particles. A powdered reactant has a greater surface area than the same reactant as a solid chunk. In order to increase the surface area of a substance, it may be ground into smaller particles or dissolved into a liquid. In solution, the dissolved particles are separated from each other and will react more quickly with other reactants. 
Story: Two groups of friends went camping , but camped separately a few hundred yards away and started a fire each. Both groups had the same volume of wood. Group P had larger logs, while group Q had small twigs, sawdust and kindlings. 
Question: Which group had wood that provided a smaller surface area for the fire to burn?
Group P.