You are choosing a book from your friend’s book collection. you can choose 1 of 6 science fiction books, 1 of 2 mystery books, or 1 of 3 biographies. how many ways can you choose a book? 11243036i am thinking that it's 11 but plz tell me if i'm  wrong!

According to modern science, earth is about 4.5 billion years old and written human history extends back about 10,000 years. suppose the entire history of earth is represented with a 10-meter-long timeline, with the birth of earth on one end and today at the other end.

Ineed i been stuck on this question since yesterday

After t seconds, a ball tossed in the air from the ground level reaches a height of h feet given by the equation h = 144t-16t^2. after how many seconds will the ball hit the ground before rebounding?