Betty can mow a lawn in 20 minutes. Bullwinkle can mow the same lawn in 60 minutes. How long does it take for both Betty and Bullwinkle to mow the lawn if they are working together? Express your answer as a reduced fraction.

What are “like terms”? why can we only add like terms?

You were told that the amount of time lapsed between consecutive trades on the new york stock exchange followed a normal distribution with a mean of 15 seconds. you were also told that the probability that the time lapsed between two consecutive trades to fall between 16 to 17 seconds was 13%. the probability that the time lapsed between two consecutive trades would fall below 13 seconds was 7%. what is the probability that the time lapsed between two consecutive trades will be between 14 and 15 seconds?

What is the inverse of the function f(x) = 2x + 1?