Question

If four people are chosen at Random, then the probability that no two of them were born on the same day of the week is

• A. 30/49
• B. 203/225
• C. 120/343
• D. 6/49

Answer 1

Answer: (C)

120/343

Four people are chosen,

If no people have same birthdays then everyone has a different birthday.

So, the probability that no two people have same birthday is $=\frac{7}{7}\times \frac{6}{7}\times \frac{5}{7}\times \frac{4}{7}=\frac{120}{343}.$

$\therefore$ Option C is correct.

Hence, the answer is $\frac{120}{343}.$