a highschool janiyor has 140 keys on his key chain. of these 140 keys, 100 open classroom doors, 80 open the door to the teachers’ lounge, and 60 open classroom doors and

Adepartment store purchases screen-printed t-shirts at a cost of $5 per shirt. they mark up the price 150% (making the selling price 250% of the store's purchase price) and put them on the sales floor. every month that a t-shirt doesn't sell, the store reduces the selling price by 25%.

Last year, a state university received 3,560 applications from boys. of those applications, 35 percent were from boys who lived in other states. part a)how many applications did the university receive from boys who lived in other states? part b)applications to the university from boys represented 40percent of all applications. how many applications did the university receive in all? i don't how to do part b so me and plz tell how you got your answer

School has 204 sixth grade students. if the sixth grade is 30% of the total school, how many students are in the middle school?