21,000 round to the nearest ten thousand

In a school 2/3 of the students study a language of those who study a language 2/5 study french

Aball is thrown from a height of 139 feet with an initial downward velocity of 15 ft/s. the ball's height h (in feet) after t seconds is given by the following. h=139-15t-16t^2 how long after the ball is thrown does it hit the ground? round your answer(s) to the nearest hundredth. (if there is more than one answer, use the "or" button.) t =

In a class, there are 12 girls. if the ratio of boys to girls is 5: 4 how many boys are there in the class