Colin got 16 out of 80 correct in his test. What fraction of the marks did he get correct? Give your answer in its simplest form.

Can someone show me the steps to solve the problem?

What is the first step of an indirect proof of a number that is divisible by two

Rockwell hardness of pins of a certain type is known to have a mean value of 50 and a standard deviation of 1.1. (round your answers to four decimal places.) (a) if the distribution is normal, what is the probability that the sample mean hardness for a random sample of 8 pins is at least 51?