Atank can be filled by one pump in 50 minutes and by another in 60 minutes. a third pump can drain the tank in 75 minutes. if all 3 pumps work simultaneously, how long will it take to fill the tank?

What is the simplified form of 7 √x • 7 √x • 7 √x • 7 √x?

Which equation represents the partial sum of the geometric series?

Rockwell hardness of pins of a certain type is known to have a mean value of 50 and a standard deviation of 1.1. (round your answers to four decimal places.) (a) if the distribution is normal, what is the probability that the sample mean hardness for a random sample of 8 pins is at least 51?