A train leaves Little Rock, Arkansas, and travels north at 60 kilometers per hours. Another train leaves at the same time and travels south at 65 kilometers per hour. How long will it take before they are 509 kilometers apart?

The graph shows the decibel measure for sounds depending on how many times as intense they are as the threshold of sound. noise in a quiet room is 500 times as intense as the threshold of sound. what is the decibel measurement for the quiet room? 20 decibels28 decibels200 decibels280 decibels