Teesha is in the French club. There are 29 students in the club. The French teacher will pick two students at random to guide visiting students from France. What is the probability that Teesha will not be picked as a guide?
The probability of Teesha not being picked as a guide can be found by first calculating the total number of possible pairs of students that can be picked for the guiding role and then subtracting the number of pairs that include Teesha.
The total number of possible pairs can be found using the formula for combinations:
nC2 = n! / (2!(n-2)!)
where n is the total number of students in the French club.
In this case, n = 29, so the total number of possible pairs is:
29C2 = 29! / (2!(29-2)!) = 406
Now we need to calculate the number of pairs that include Teesha. Since there are 28 other students in the club, Teesha can be paired with any of them to form a guiding pair. This means there are 28 possible pairs that include Teesha.
So the probability of Teesha not being picked as a guide can be calculated as:
(number of pairs that don't include Teesha) / (total number of possible pairs)
= (406 - 28) / 406
= 378 / 406
= 0.931034
Therefore, the probability that Teesha will not be picked as a guide is approximately 0.931 or 93.1%.