A mine produces 42.5 tons of coal per hour. How much coal will the mine produce in 9.5 hours?

If the ratio of sum of the first m and n terms of an ap is m2 : n2 , show that the ratio of its mth and nth terms is (2m − 1) : (2n − 1).

Which geometric principle is used to justify the construction below?

Tyler reads 2/5 of a book on monday, 1/3 of it on tuesday, 2/9 of it on wednesday, and 3/4 of the remainder on thursday. if he still has 14 pages left to read on friday, how many pages are there in the book?