Event a has a 0.3 probability of occurring and event b has a 0.4 probability of occurring. a and b are independent events. what is the probability that either a or b occurs?

International calls require the use of a country code. many country codes a 3-digit numbers. country codes do not begin with a 0 or 1. there are no restrictions on the second and third digits. how many different 3-digit country codes are possible?

Which shows one way to determine the factors of 4x3 + x2 – 8x – 2 by grouping?

Aconstruction worker has rope 9 m long he needs to cut it in pieces that are each 3 /5 m long how many such pieces can he cut without having any rope leftover?