Using a telescope consisting of a lens with a focal length F1 = 50 cm and a diameter d1 = 10 cm and an eyepiece with a focal length F2 = 2.5 cm and a diameter d2 = 0.5 cm, an image of the Sun was obtained on a screen located on distance b = 20 cm behind the eyepiece. Determine how many times the illumination of the image is greater than the illumination of the screen by direct sunlight. The angular diameter of the Sun is a = 0.01 rad. Neglect light losses in the optical system.

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