Correct answer only ! i cannot retake what is the weight of a ring tailed lemur that has a mass of 10 kg? use w = mg (g = -9.8 m/s^2)

From center station, a train departs every 30 minutes on the fast line and a train departs every 50 minutes on the state line. if two trains depart from center station at 8: 00 a.m., one on each of the two lines, what is the next time that two trains, one on each line, will depart at the same time?

Could someone me find the answer to this problem.

At very high pressures, gases become and will eventually a) more dense; become hotter b) more dense; change to a liquid or solid c) less dense; combust d) less dense; turn into a liquid