Mr. rodriguez, a college instructor, can grade his class papers in 3 hours while it takes his assistant 4.5 hours. if mr. rodriguez graded the papers for 1 hour and then left the job for his assistant to complete, how long will it take his assistant to finish grading papers?

The rate of mr Rodriguez to complete 1 job is 1/3 while that of his assistant is 1/4.5.

So if mr Rodriguez works for 1 hour, the job left would be 2/3 of the job. So the total time needed by assistant is:

(2/3) / (1/4.5) = 3 hours

3 hours

answer set (b) 0.5, 3/4 80% is in order from least to greatest.  

step-by-step explanation:

in order to compare rational numbers to each other, it is much easier if they are in the same form.   typically, the best form in which to evaluate rational numbers is in decimals.   in order to convert a percent to a decimal, you would divide the given percentage by 100.   you can also accomplish the conversion by moving the decimal point over two places to the left.   for example, the decimal value of 80% is 80/100, or 0.8.   in order to convert a fraction to a decimal, you need to divide the numerator by the denominator.   for example, 3/4 is 0.75.   so, for choice (b) 0.5 3/4 (0.75), 80% (0.8) is the only choice in which the numbers are in order from least to greatest.