Jack bought 2 umbrellas and 3 hats $18.00. each umbrella costs the same amount. each hat costs the same amount. the price of hat is $4.00. what is the cost of 1 umbrella?

An advertising firm has an old computer that can prepare a whole mailing in 6 hours. with the of newer model the job is complete in 2 hours. how long would it take the newer model to do the job alone?

Suppose you want just guess at the answers in a 5 question multiple-choice test. each question has 3 responses and only one is correct. what is the probability of getting two questions right just guessing? 20 points 0.3275 0.2753 0.7532 none of the above

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?