and q →r , then you can use the law of transitivity to conclude
q→r.
That is a basic law of sillogisms.
An example will help you to understand the transivity law:
Make p, stand for 3 > 3/4, q stand for 3/4 > 15 / 20, the you can conclude that 3 > 15 / 20.
3 > 3/4
3 /4 > 15 / 20
Then, 3 > 15 /20.
This is, from the fact that you know that 3 is gretar than 3/4 and that 3/4 is greater than 15/20, you can conclude that 3 > 15 / 20. That is transitivity and is a law of logic, which you can use to get conclusions.
