How many prime numbers are greater than 20 and less than 30

Two trains leave stations 546 miles apart at the same time and travel toward each other. one train travels at 95 miles per hour while the other travels at 115 miles per hour l. how long will it take for the two trains to meet

Write the point-slope form of an equation of the line through the points (-2, -3) and (-7, 4).

Factor the gcf out of the polynomial 9x^6+6x^4+15x^3