Let a Be the Set of All Strings of Decimal

question 147

Short Answer

let A be the set of all strings of decimal digits of length five. For example, 00312 and 19483
are strings in A.
-How many strings in A have exactly three 5s?

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Definitions:

Fat and cholesterol

Substances found within the body and foods that are essential for health but can lead to heart disease when consumed in excess.

Infant digestive systems

The developmental physiological system in infants that processes and absorbs nutrients from ingested food, adapting as the infant grows.

Food allergies

An immune system response that occurs soon after eating a certain food, causing various symptoms which can range from mild to severe.

Aversion to foods

A strong dislike or disinclination towards certain foods, often due to taste, texture, or past negative experiences.