Answer following physics questions

Consider the diagram below showing light interacting with three different media. Based on your understanding of refraction, which of the following statements is correct? medium 1 medium 2 medium 3 On1 > n2 > n3 On1 > n3 > n2 On3 > n2 > n1 On2 > n1 > n3Below are pairs of radii for thin lenses. Which of the following pairs would result in the formation of a real image when an object is placed 50 cm from the lens (the lens has an index of refraction of 1.5) Or1 = 20 cm and r2 = 40 cm Or1 = 20 cm and r2 = -20 cm Or1= -40 cm and r2 = 40 cm Or1 = -20 cm and r2 = 40 cmAn object is placed 15 cm from a lens with a power of 2.0 D. The image produced will be 0 larger, upright and imaginary 0 larger, inverted and real 0 smaller, upright and imaginary 0 smaller, inverted and real