How much light is refracted in glass?

Correct answer: c 96%

An ordinary piece of glass reflects only 4% to 5%; the rest, about 95% to 96%, is refracted through. Of the options, 96% matches that share.

Why the other options are wrong

• a 4%: This is not the answer: 4% to 5% is the share an ordinary piece of glass reflects, not the share it refracts. The rest, about 95% to 96%, goes through.
• b 5%: This is not the answer: 5% is the upper end of the reflected share, not the refracted one. The rest, about 95% to 96%, goes through.
• d 100%: This is not the answer: All of it cannot be refracted, because 4% to 5% is reflected back from the glass.