In a certain game a player can solve easy or hard puzzles

Earth's atmosphere is unique among the planets and is able to support life because it contains a large amount of a) oxygen b) helium c) methane d) carbon dioxide

Compare the advantages and disadvantages of using cash instead of a credit card to obtain good services

Simba travel agency arranges trips for climbing mount kilimanjaro. for each trip, they charge an initial fee of \$100$100 in addition to a constant fee for each vertical meter climbed. for instance, the price for climbing to the shira volcanic cone, which is 30003000 meters above the base of the mountain, is \$400$400. let f(d)f(d) denote the fee of a trip ff (measured in dollars) as a function of the vertical distance climbed dd (measured in meters). write the function's formula. f(d)=