WORD CHOICES

A COMMON SLIP

John, Will and Andrea were playing marbles and between them there were 73 marbles.
Is there an error here?

TODAY'S WORD

The word for today is concomitant. This is an uncommon word; I just like its sound.
Define concomitant and use it in a sentence.

Corrections and explanations for this past week's efforts will be posted some time tomorrow.