What approximate focal length of the objective lens will give a total magnification of 200×? assume a length l = 160 mm.

Jerrold has to buy 12 copies of a textbook which costs $36.25 per copy. how much must he spend for them?

Trey has answered 15 e-mails. this is 20% of e-mails he must answer. how many e-mails does he need to answer? pls ; op'; ; p'[o; pio; uiylutryte

Layer r contains a well-known index fossil that is 100 million years old. based on this information and the principle of superposition, a. layers t and m are older than 100 million years, and layers x and g are younger than 100 million years. b. layers t, m, x, and g are all older than 100 million years. c. layers t and m are younger than 100 million years, and layers x and g are older than 100 million years.