The ratio of seventh graders to eight graders participating in the science fair is 4:3. There are 18 eight graders participating in the science fair. How many 7th graders are there?
At Discount Copy, 12 copies cost $0.66. Melissa needs 56 copies. How much should they cost?
The ratio of teachers to students needs to be 1:30. If there were 120 students, how many teachers would be needed?