The maximum efficiency a real engine (that involves irreversible processes) can possibly achieve when operating between temperatures 100k and 1000k among the choices below is

Given a circle with measures of (c, d, and r) and a circle with measures of (c', d', and r'), what is d if c c' = 12 and d' = 0.50? a) 3 b) 6 c) 12 d) 24

How do i do this activity, is appreciated

The probability that a student graduating from suburban state university has student loans to pay off after graduation is .60. if two students are randomly selected from this university, what is the probability that neither of them has student loans to pay off after graduation?