This questions is extremely hard, could someone please answer what 5+8 is?

Asphere has a diameter of 10 in. what is the volume of the sphere?

An arc subtends a central angle measuring 7pi/4 radians what fraction of the circumference is this arc?

An energy drink company claims that its product increases students' memory levels. to support its claims, the company issues advertisements claiming that 8 out of 10 people (chosen randomly from across the country) who tried their product reported improved memory. the missing component in this study is a .