Statistic question?

a burglar alarm system has six fail-safe components. The probability of each failing is o.oo5. Find these probabilities: Exactly 3 will fail, fewer than 2 will fail and none will fail. Then compare the answers and explain why the results are reasonable. I got the number for the first 3 question, but i still confused about the last one. Explain why the result are reasonable??? Can you give me your ideas?