Answer students' questions and become popular!

Question is not from a book. its from a class.
Suppose a bag contains at total of 5280 quarters; some of which are Canadian and some of which are US. The Canadian dollar is worth 87 US cents. An ounce of gold is worth US$ 989.
a) If the number of US coins the bag contains is N, write an algebraic expression for how many US dollars they are worth. [Hint: how much is one quarter worth? Two quarters? N quarters?]

b) Write an expression for how many ounces of gold the US coins will buy. [Hint: how do you determine how much of something you can get for a given amount of money based on its price?]

c) Write an expression in terms of N (the number of US coins) for the number of Canadian coins in the bag. [Hint: the whole is the sum of the parts. What number is given as the whole?]

d) Give an expression (in terms of N, the number of US coins) for how many US dollars the Canadian coins are worth. [Hint: how many Canadian dollars are the Canadian coins worth and how much in US dollars is a Canadian dollar worth?]

e) Write an expression (in terms of only the variable N, the number of US coins) for how many ounces of gold the Canadian coins will buy. [Hint: how do you find how much of something you can buy for a given amount of money based on its price?]

f) Write, and then simplify (by collecting like terms, etc.), an expression, in which N (the number of US coins) is the only variable, for the amount of gold that the whole bag will buy. [Hint: The whole is the sum of the parts.]