The probability that a fish of a certain species survives more than 5 years is 10\%. Find: a) (1 point) If in an aquarium we have 10 fish of this species born this year, find the probability that at least two of them are still alive in 5 years. b) ( 1.5 points) If in a tank of a fish farm there are 200 fish of this species born this same year, using an approximation by the corresponding normal distribution, find the probability that after 5 years at least 10 of them have survived.