Person 1 can do a certain job in fifteen minutes, and person 2 can do the same job in thirty minutes. when completing the job together, which expression would be used to represent the amount of work done by person 1?

Plzzz plzz maths ! quadratic sequences =an^2+bn 1) 1,6,15,28,45 2)5,18,39,68,105 3) 1,8,21,40,65 4) 7,24,51,88,135 5) -1,2,9,20,35

How do i start to solve? would appreciate a walk-thru! a bird sitting 16ft above the ground in an apple tree dislodges an apple. after how many seconds does the apple land on the ground? (assuming that no branches will interfere with it's fall)

Which is the solution to the inequality? 2 3/52 1/15 b< 3 2/15 b> 3 2/15