John was competing in a 1000 meter race. he had to pull out of the race after running 2/4 of it. how many meter did he run?

Which is the equation of an ellipse with directrices at x = ±4 and foci at (2, 0) and (−2, 0)?

Me. i can't figure out this question. give an explanation too. .

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).