If you got (B), you found the number of novels Virginia Woolf wrote and stopped there.
The printer conveniently prints at a rate of 300 pages per hour, so it will take one hour to print 300 pages.
(C) and (D) are incorrect because the question tells you nothing about the number of students at each university.
If you got (D), you found the number of pieces total in the store before any were bought.
(A) is incorrect since b must be negative, because at some positive x-value the function is negative, but ax2 and c are both still positive, so bx must be negative, meaning b is negative.
(B) is incorrect because b – a is a negative number minus a positive number, which will always be negative.
(C) is incorrect because c is positive, so -c is negative.
Now that both sides have the same denominator of , you can set the numerators equal to each other to get . Since the question gives you the value of A, you can start by plugging in 2.5 where A appears. It may help to then multiply each term by 2 to eliminate the decimal in the coefficient 2.5:
From here, distribute the 5 and move the resulting terms to the left side of the equation:
You should now notice that also shares the factor , so you can factor the left side of the equation and divide both sides by :
You now know that . Therefore,
The total distance she ran in an hour is M + N, which will be 1(6) + 0.5(1 – 0.5)(2) = 6.5 miles.
Alternately, you can recognize that her speed in mph is equal to the distance, miles, divided by time, hours. So, the distance can be found by multiplying the speed by the time. You can see that she ran 3 miles in the first half hour, because .5 hours × 6 mph = 3 miles. In the second half hour, she starts at 6mph and ends at 8mph, making her average speed 7mph. So, .5 hours × 7 mph = 3.5 miles. Finally, 3 miles + 3.5 miles = 6.5 miles.