Answer:
The probability of drawing exactly two 4, 5, 6, or 7 s is
.
Explanation:
In a standard deck the total number of cards is 52.
There are 4 different suits and each suit have 13 different cards.
13 different cards for one spaed , 13 different card of club, 13 different card of diamond and 13 different card of heart.
So we have 4 card of each number.
The total card of 4,5,6 and 7 s are
![4* 4=16](https://img.qammunity.org/2019/formulas/mathematics/college/lclx4logg6jboc032hjbrdvm7xuz8phi03.png)
The number of cards which are not 4,5,6 and 7 s,
![52-16=32](https://img.qammunity.org/2019/formulas/mathematics/high-school/4webq8zidmcc56ov31j6kqllyk29wofief.png)
Use combination to find the probability of drawing exactly two 4, 5, 6, or 7 s.
We have to select 2 card from 16 card, 1 card from another 32 card and 3 card from 52 card.
![P=\frac{\text{possible outcomes}}{\text{Total number of outcomes}}](https://img.qammunity.org/2019/formulas/mathematics/high-school/hioowxx0ip0m67dhwl29z4gv5zh4d4z7jk.png)
![P=(^(16)C_(2)* ^(36)C_(1))/(^(52)C_(3))](https://img.qammunity.org/2019/formulas/mathematics/high-school/hrq0tj2pncn8wqhqme7ji2hdl6vfdctrqv.png)
![^(n)C_(r)=(n!)/(r!(n-r)!)](https://img.qammunity.org/2019/formulas/mathematics/high-school/yw2gcdssrr7wssp3smywi8cgbhjohq5ssb.png)
![P=(120* 36)/(22100)](https://img.qammunity.org/2019/formulas/mathematics/high-school/n5aox89d6v5eye19jby6ofauzhlnqkwaqp.png)
![P=(216)/(1105)](https://img.qammunity.org/2019/formulas/mathematics/high-school/2k5px9byroavog6azv9chvoq44vmrqcg0x.png)
Therefore, the probability of drawing exactly two 4, 5, 6, or 7 s is
.