posted by Jon .
1)An object of height 4 cm is placed at a distance of 20 cm from a convex lens of focal length 10 cm. Find the nature of the image.
-4 or 4 away
answer: real, inverted
2)Light passes from air into water at 45.0 d/C to the normal. If the index of refraction of water is 1.33, find the angle of refraction.
The numbers are correct, but I am not familiar with your "d/C" notation. I hope it has nothing to do with degrees C, which is a unit of temperature, not angle. Angle-measuring units are just called "degrees".