They must be homozygous for that trait
Population density =number of individual divided land area
land area should be in square kilometers
therefore 120 ha =120 x0.01=1.2 square kilometer since 1 ha=0.01 kilometer square
total population= (80 x 1500)/100=1200
population density is therefore=1200/1.2=1000

velocity is a vector so it has a magnitude and direction so the answer would be B
An educated guess that is aslo posed as a tentative explanation is called a hypothesis.