6· [10pts] a 300-gal tank initially contains 100 gal of brine containing 30 lbs of salt. brine containing 1 lb of salt per gallon enters the tank at the rate of 6 gal/s, and the well-mixed brine in the tank flows out at the rate of 4 gal/s. how much salt will the tank contain when it is full of brine? it's the question about elementary differential equation. provide specific solution and explanation with clear handwriting.

1- 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.2- 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 the first question?

The function models the number of accidents per 50 million miles driven as a function

An office supply company conducted a survey before marketing a new paper shredder designed for home use. in the survey, 80 % of the people who tried the shredder were satisfied with it. because of this high satisfaction rate, the company decided to market the new shredder. assume that 80 % of all people are satisfied with this shredder. during a certain month, 100 customers bought this shredder. find the probability that of these 100 customers, the number who are satisfied is 69 or fewer.