what is meant by perpetuity? I have pasted some questions below.

Organizations use all types of investments to keep the organization in business for as long as possible. As you pointed out, one such investment is a perpetual annuity - "an annuity for an infinite period of time" (Zelman et al., 2014, p. 280). Zelman gives us a pretty good example. In their example, how do they calculate the rate of return? How does a perpetual annuity compare to other annuities?