if you started with a sample of 600 radioactive nuclei, how many would remain active after 3 half lives?

Why don't you see your reflection in water with waves or repples

Two rigid transformations are used to map δhjk to δlmn. the first is a translation of vertex h to vertex l. what is the second transformation? a reflection across the line containing hk a rotation about point h a reflection across the line containing hj a rotation about point k

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