To meet small obligations and finances.

ex. Petty cash maintenance - Impractical to use check or other form of cash just to purchase small amount...

For the same reason you carry around 20 to 40 dollars when going out into the city. Just to be safe. For example if there is a down turn. to keep liquid

Companies hold cash to make necessary payments, to take advantage of opportunities as they arise, and to cover unforeseen emergencies.

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very simple! to meet out the expenses