True that is the correct definition of supply. Demand is what the name suggest it Is the demand or need for a material or merchandise. Supply is the ability to meet the demand or the defintion you just described. Supply and demand is what makes things that should be cheap expensive and the expensive things cheap.
The questionnaires are a cheap and quick and the effective way to obtain large amounts of information form a large sample of people. As they are open and closed type they give the respondent enough time to think and respond and are beneficial for the quantitative and the qualitative data.
