Say whether each of these statements about square numbers is always true, sometimes true or never true a the last digit is 5
b the last digit is 7
c last digit is a square number.
last digit is not 3 or 8​

Atrain leaves little? rock, arkansas, and travels north at 90 kilometers per hour. another train leaves at the same time and travels south at 80 kilometers per hour. how long will it take before they are 680 kilometers? apart?