hi! i need help with question 7. for a) i got 3/40 is that right? if not pls explain

and i need help for b too tysm!

and for question 6 i asked how to do it but this random person on this website spammed me in an unknown language instead of answering:(

A counter will then be p (a) Work out the probability that Box A will Box A end up containing 3 white counters. 5 O (b) Work out the probability that Box A will w end up containing exactly 2 white counters. Box B 6. A jar contains eight 10p coins and six 7. Each day, there is a 40% chance that Luke 5p coins. Three coins are picked at will cycle to work, otherwise he will take the random from the jar, without replacement. bus. (a) Work out the probability that the total If he cycles, there is a 5% chance he will value of the three coins is 30p. 3 arrive late. If he takes the bus, there is a 15% chance he will arrive late (b) Work out the probability that the total (a) Work out the probability that Luke will value of the three coins is 15p. arrive late to work on any given day. (b) Given that Luke was late one day, work (c) Work out the probability that at least out the probability that he had cycled on this one of each type of coin is picked day. 8. A particular disease a of the trees in a forest. A test on a sample from the tree has a 90% chance of showing based. The test has a 15% chance of show