# Fish tank

A fish tank at a pet store has 8 zebra fish. In how many different ways can George choose 2 zebra fish to buy?

Result

n =  28

#### Solution:

$x = C_{{ 2}}(8) = \dbinom{ 8}{ 2} = \dfrac{ 8! }{ 2!(8-2)!} = \dfrac{ 8 \cdot 7 } { 2 \cdot 1 } = 28$

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