How was the problem of what to do with Bruno finally solved?

How is the problem solved?

Most herbivores have a problem. What is it? How can it be solved?

A can solve 75% of the problems in a book on mathematics and B can solve 70%. What is the probability that a problem chosen at random is solved?

A problem in Mathematics is given to three students whose chances of solving it are 1/3, 1/4, and 1/5 (i) What is the probability that the problem is solved ? (ii) What is the probability that exactly one of them will solve it ?