Plz help really important to my grade

Select the correct answer. joshua likes to read. he read 6 books when he was 6 years old. every year he doubled the number of books he read the previous year. how many total books did he read between the ages of 6 and 10? a. 60 b. 90 c.186 d.187

The parabola opens: y=√x-4 (principal square root) up down right left

When you flip a biased coin the probability of getting a tail is 0.6. how many times would you expect to get tails if you flip the coin 320 times?