Courtney flips a fair coin four times. what is the probability that the coin will come up heads four times in a row?

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)

Given: △acm, m∠c=90°, cp ⊥ am , ac: cm=3: 4, mp-ap=1. find am.

50 points~ ! i have to turn this in tomarrow