In hillcrest school, 36% of middle school students are in grade 6, 31% are in grade 7, and 33% are in grade 8. if a middle school student is selected randomly, what is the probability that the student is either in grade 6 or in grade 7? a) 0.31 b) 0.33 c) 0.64 d) 0.67

Sarah took the advertising department from her company on a round trip to meet with a potential client. including sarah a total of 11 people took the trip. she was able to purchase coach tickets for $280 and first class tickets for $1280. she used her total budget for airfare for the trip, which was $6080. how many first class tickets did she buy? how many coach tickets did she buy?

Over which interval is the graph of f(x) = x2 + 5x + 6 increasing?

The cost of using a service is $0.25 per min. what equation correctly represents the total cost c, in dollars, for d days of use?