Answer:
2775 ways
Step-by-step explanation:
We have been given the case to choose exactly two tails when flipped 75 times means \(^{75}C_2\)
Since, \(^nC_r\) is equal to \(\frac{n!}{r!\cdot(n-r)!}\)
Here n =75, r=2 substituting the values we will get
\(\frac{75!}{2!(75-2)!}\)
\(n!=n\cdot (n-1)\cdot (n-2).....1\)
After simplification we will get \(\frac{75\cdot 74\cdot 73!}{2!\cdot73!}\)
Cancel out the common term that is 73! we will get
after more simplification we will get \(\frac{75\cdot 74\cdot}{2!}\)
Finally, we will get \(\frac{75\cdot 74\cdot}{2}=75\cdot37=2775\)
