At a farm, a crate of fruits can hold 30 bananas. If a farm worker can fill 10 crates in a day and the farm has 42 farm workers, how many bananas can be packed into crates in 9 days?
Siti has 3 pairs of white socks and 7 pairs of black socks. All the socks are in a bag. If Siti picks the socks without looking at them, how many socks she has to remove from the bag before she can be sure that she has a pair of black color?