Statistics and Probability Answers

Distinguish between a systematic and a random error in the measurement of a physical quantity.

A particle flies through the absorbing screen with the probability 0.01. What is the expected value of the number of flown through the screen particles if the total number of them is 100? How large is the probability that more than 11 particles can fly through the screen?

5 people left their hats in the wardrobe. Then everybody took a hat randomly. What is the probability that everyone took not his hat?

There are 9 white balls and 1 red ball in the box. What is the probability to pick a red ball at least once in 10 extractions (if the balls are returned back after each extraction)? How many extractions should be done to pick the red ball with the probability not less than 0.9?

Neutrinos fly through the Earth with the probability 249999/250000. What is the probability for it to fly through 250000 globes; 500000 globes?

Can the following formula be correct: P{(A1 ∪ A2)/B} = P{A1/B} + P{A2/B}, if A1A2 is not an empty event?

When it is more likely to guess a result: if it is known that the sum of the points when throwing two dices is 7 or 10?

A particle can be absorbed by a screen with the probability 0.5. What number of such screens should be placed one after another to absorb a particle with the probability not less than 0.999?

What is more likely: get a coat at least once or get tails twice while throwing a coin twice?

Simplify: (A ∪ B)(A ∪ B').