A company has two large computers. The slower computer can send all the company's email in 45 minutes. The faster computer can complete the same job in 15 minutes. If both computers are working together, how long will it take them to do the job?

Aclass consists of 55% boys and 45% girls. it is observed that 25% of the class are boys and scored an a on the test, and 35% of the class are girls and scored an a on the test. if a student is chosen at random and is found to be a girl, the probability that the student scored an ais

Ammonia molecules have three hydrogen atoms and one nitrogen atom. how many of each atom arein five molecules of ammonia

If your teacher tells you to do questions 6 through 19 in your math book for homework, how many questions is that