7 Froox sweets are packed into tubes of 10 sweets, chosen at random. \(25 \%\) of Froox sweets are yellow.
- Find the probability that in a randomly selected tube of Froox sweets there are
(a) exactly 3 yellow sweets,
(b) at least 3 yellow sweets. - Find the probability that in a box containing 6 tubes of Froox sweets, there is at least 1 tube that contains at least 3 yellow sweets.