Answer:
Associative property of multiplication
Step-by-step explanation:
By the associative property of multiplication,
During multiplying three terms we can multiply any of two first ( that is we can grouped any two by parenthesis )
if a, b and c are any number,
\(\implies (a\times b)\times c=a\times (b\times c)\)
Hence, in the problem,
\((3\times 10)\times 8=3\times (10\times 8)\)
Associative property of multiplication is used.