Will mark brainlist!! please help ​

Jenisey has $24 to spend on seven pencils. after buying them she had $10. how much did each pencil cost.?

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

Each cookie sells for $0.50 sam spent $90 on baking supplies and each cookie cost $0.25 to make how many cookies does sam need to sell before making a profit formula: sales> cost