Help plz (asap) .

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)

If x is 6, then 7x= a. 13 b. 42 c. 42x d. 76

15m is what percent of 60m; 3m; 30m; 1.5 km? the last one is km not m