How to find how many times in the second test would you except score to be at least 600

Which equation represents a proportional relationship that has a constant of proportionality equal to 1/5

Dylan and dusty plan to take weekly surfing lessons together. if the 2-hour lessons are $20 per person and they plan to spend $100 each on new surfboards, what is the maximum number of lessons the two can take if the total amount spent for lessons and surfboards is at most $480?

What is the order of these fractions from least to greatest 2/3 7/10 5/8 65/100