I order 700 notebooks by accident. I only need 3⁄7 of my order. How many notebooks do I return?

The area of a 25-inch tv screen is 300 square inches. the area of a 40-inch tv screen is 768 square inches. the are of the smaller screen is what percent of the area of the larger screen?

8000 + 8800 + 8000 + 8 million + 80 trillion + another a katrillion equals

With finding limits of multi variable !