A set of two concentric circles is shown above. What is the area of the shaded portion above?​

Idon’t understand this.. will someone ? will mark brainliest along with 20 points.

Carli has 90 apps on her phone. braylen has half the amount of apps as theiss. if carli has three timesthe amount of apps as theiss,how many apps does braylen have? let b represent the number of braylen's apps and t represent the number of theiss's apps.

Given a normal distribution with µ =50 and σ =4, what is the probability that 5% of the values are less than what x values? between what two x values (symmetrically distributed around the mean) are 95 % of the values? instructions: show all your work as to how you have reached your answer. don’t simply state the results. show graphs where necessary.