Answer: 105
Step-by-step explanation:
Since we are choosing 2 out of 15 members, then the formula to use will be the combination formula which will be:
= n! /r! (n - r)!
where,
n = total members = 15
r = number of items to choose = 2
Slotting this into the formula will give:
= n! /r! (n - r)!
= 15!/2! (15-2)!
= 15!/2! 13!
= (15 × 14) / (2 × 1)
= 105
The club can choose the co-president in 105 ways.