I need to know how to do this math problem

An ulcer medication has 300 milligrams in 2 tablets. how many milligrams are in 3 tablets?

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)

When 142 is added to a number the result is 64 more then 3 times the number. option 35 37 39 41