Question Number 131744 by bemath last updated on 08/Feb/21
![](https://www.tinkutara.com/question/18556.png)
Answered by liberty last updated on 08/Feb/21
![= C_3 ^7 = ((7.6.5)/(3.2.1)) = 35](https://www.tinkutara.com/question/Q131746.png)
$$=\:\mathrm{C}_{\mathrm{3}} ^{\mathrm{7}} \:=\:\frac{\mathrm{7}.\mathrm{6}.\mathrm{5}}{\mathrm{3}.\mathrm{2}.\mathrm{1}}\:=\:\mathrm{35}\: \\ $$