Liam does 165 sit-ups every day. How many sit-ups does he do in 7 days?

Can any one me with the answers to these questions asap?

1- is the product of two rational numbers irrational or rational? first, make a hypothesis by multiplying two rational numbers. then, use variables such as x=a/b and y=c/d and the closure property of integers to prove your hypothesis. 2- what do you think the product of a nonzero rational number and an irrational number is? is it rational or irrational? make use of variables, the closure property of integers, and possibly a proof by contradiction to prove your hypothesis. 3- why do we have to specify that the rational number must be nonzero when we determine what the product of a nonzero rational number and an irrational number is? if the rational number were 0, would it give us the same result we found in part b?

Question 4 of 10 2 points what is the second part of the process of investigating a question using data? a. rephrasing the question o b. describing the data c. collecting the data o d. making an inference submit