# Let * be a binary operation on N given by $$a*b=H.C.F.(a,b), a,b \in N.$$ Write value of 22*4.

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• The highest common factor (HCF), of two or more non-zero integers, is the largest positive integer that divides the numbers without a remainder.
$a\ast b$=HCF(a,b)
$22\ast 4$=HCF(22,4)
$22=2\times 11$
$4=2\times 2$
$\therefore HCF =2$
answered Nov 7, 2013