Part B. Numerical Response.
1. During college orientation week, organizers promise that all students who attend the morning orientation session will win a prize. A few of the prizes are expensive mobile phones and digital cameras, and all of the other attendees will win a college tote bag. The probability of winning a tote bag is \( \frac{21}{22} \). If the odds of winning one of the more expensive prizes is expressed as \( a: b \), then what is \( a+b \) ? \( \qquad \)