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Numbers with only two factors, one and itself are called numbers.

Fill in the blanks.

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A set of three consecutive prime numbers differing by $2$ is called a _____.

Answer True (T) or False (F).

Two composite numbers are never co-prime.

The H.C.F. of two numbers is always a factor of their L.C.M.

Answer True (T) or False (F).

Two consecutive numbers are always co-prime.

Answer True (T) or False (F).

The H.C.F of two multiples of $10$ is always $10$.

Which of the following should be performed first to simplify the expression:

$(24\times 3)+(16÷8)-12÷2+1$