Chose whether the probability is mutually exclusive or not P(A) = 2/5 P(B) = 1/2 P(A or B) = 9/10

What is the product of the radical expression. (7-2square root) (8+2 square root)

Fredrick designed an experiment in which he spun a spinner 20 times and recorded the results of each spin

Arley is building a model of a city map. in one part of the city, three roads form a right triangle, which harley draws as triangle abc, with the following measures: m∠b=90° and m∠a=30°. in his scale model, the hypotenuse of triangle abc, ac¯¯¯¯¯¯¯¯, has a length of 817−−√ cm. what is the value of a (the length of bc¯¯¯¯¯¯¯¯)?