Charmaine purchased a prepaid phone card for $20 . long distance calls cost 19 cents a minute using this card. charmaine used her card only once to make a long distance call. if the remaining credit on her card is $17.15 , how many minutes did her call last?

The distance around the lake is 2 kilometers. ifelena wants to run 14 kilometers this week, howmany laps must she run around the lake

Browning labs is testing a new growth inhibitor for a certain type of bacteria. the bacteria naturally grows exponentially each hour at a rate of 6.2%. the researchers know that the inhibitor will make the growth rate of the bacteria less than or equal to its natural growth rate. the sample currently contains 100 bacteria.the container holding the sample can hold only 300 bacteria, after which the sample will no longer grow. however, the researchers are increasing the size of the container at a constant rate allowing the container to hold 100 more bacteria each hour. they would like to determine the possible number of bacteria in the container over time.create a system of inequalities to model the situation above, and use it to determine how many of the solutions are viable.

7. the area of the playing surface at the olympic stadium in beijing isof a hectare. what area will it occupy on a plan drawn to a scaleof 1: 500?