Geometry question help please!!

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

Angle that produces maximum distance

Study results indicate that the mean length of time people spend on a bus in a city is between 21.2 min and 24.5 min what is the study margin of the error?