(1/2)^3 x 2 need help on this

If the wwight of a package is multiplied by 7/10 the result is 65.8 find the weight of the package

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)

Solve -.016x= -16. need solving this