Questions

Only if either demand or supply was either completely elastic or inelastic will the tax burden fall entirely on either the buyer or the seller. Between these 2 extremes, tax incidence varies continuously from a perfectly inelastic supply or perfectly elastic demand, where the sellers assumes the entire burden of the tax to the perfectly elastic supply or perfectly inelastic demand where the buyers bear the entire burden. To better see how the elasticity of supply and demand affects tax incidence, consider a 20% tax on a can of soda. Suppose the government decides that the buyer should pay the 20% tax. Does this mean that the buyers will be paying 20% more, or will sellers have to share some of the tax burden? Since higher prices decrease demand, regardless of the reason for the higher prices, sellers will share some of the burden. How much of the burden will be determined by the elasticity of supply and demand for the product?

A filament is a metal wire that glows when electricity is channeled into it. The filament of an electric bulb is made of Tunsten. 

Because of its high melting point and its greatest tensile strength, it makes for a good filament in light bulbs.

If some action has started in the past and is still continuing, then present perfect continuous tense should be used instead of present continuous tense. So, the phrase ‘am waiting’ needs to be replaced with ‘have been waiting’ to make the sentence contextually correct. Thus, the correct formation would be, ‘I have been waiting for three –quarters of an hour’.