Coincidence

[Hina Muqadas]

Noteworthy [event] of having the exact [change] during small [cash] transactions.

[Sonia]

A remarkable concurrence of events or circumstances without apparent causal connection.

[Zipporah Schumaker]

A compartmentalized [serendipity] formed by an [underlying] [synchronicity].

[Monty]

Something that arises from [two] or more [original] ideas being [related].

[Raeanne Dimick]

A coincidence is a remarkable concurrence of events or circumstances that have no apparent causal connection with one another. The perception of remarkable coincidences may lead to supernatural, [occult], or [paranormal] claims. Or it may lead to belief in [fatalism], which is a doctrine that events will happen in the exact manner of a predetermined plan.
From a statistical perspective, coincidences are inevitable and often less remarkable than they may appear intuitively. An example is the birthday problem, which shows that the probability of two persons having the same birthday already exceeds 50% in a group of only 23 persons.1

[Jessica]

an [accident] of [coins]

[Jason Yan]

an occasion when two or more similar things happen at the same time, especially in a way that is unlikely and surprising: