A school has 20 classrooms. One
fourth of the classrooms are
for kindergarten and first
grade. Twice as many are
for second and third grade.
The rest are for fourth and
fifth grade. What percent
of the classrooms are for 45
or 5th graders

For a read-a-thon, jay and odhràn each started reading a book at the same time and continued reading for several hours. jay's book had 278 pages, and he read 55 pages per hour. odhràn's book had 238 pages, and he read 45 pages per hour. after how many hours did they have the same number of pages left, and how many pages were left?

The parabola y = x² - 4 opens: a.) up b.) down c.) right d.) left

Last month, a 770 g box of cereal was sold at a grocery store for $3.10. however, this month, the cereal manufacturer launched the same cereal in a 640 g box, which is being sold at $2.50. what is the percent change in the unit price?