Read the following text carefully : Government provides certain goods and services which cannot be provided by the market mechanism. Examples of such goods are national defence, roads, government administration etc. which are referred to as public goods. There are two major differences between public and private goods. One, the benefits of public goods are available to all and are not only restricted to one particular consumer. For example, if a person wears a shirt, it will not be available to others. It is said that this person's consumption stands in rival relationship to the consumption of others. However, if we consider a public park or measures to reduce air pollution, the benefits will be available to all. One person's consumption of a good does not reduce the amount available for consumption for others and so several people can enjoy the benefits, that is, the consumption of many people is not 'rivalrous'. Two, in case of private goods, anyone who does not pay for the goods can be excluded from enjoying its benefits. If you do not buy a ticket, you will not be allowed to watch a movie at a local cinema hall. However, in case of public goods, there is no feasible way of excluding anyone from enjoying the benefits of the good. That is why public goods are called non-excludable. Even if some users do not pay, it is difficult and sometimes impossible to collect fees for the public good. These non-paying users are known as 'free-riders'. Consumers will not voluntarily pay for what they can get for free and for which there is no exclusive title to the property being enjoyed. The link between the producer and consumer which occurs through the payment process is broken and the government must step in to provide for such goods. On the basis of the given text and common understanding, answer the following questions : (a) Describe how the Government's role in providing public goods impacts community welfare. (b) Define free-riders. Explain the challenges posed by the free-riders in the context of public goods.