How can you use mental math to determine if the ratio is simplified

Which ahows the graph of the solution set of 6x+4y< 12

The means and mean absolute deviations of the individual times of members on two 4x400-meter relay track teams are shown in the table below. means and mean absolute deviations of individual times of members of 4x400-meter relay track teams team a team b mean 59.32 s 59.1 s mean absolute deviation 1.5 s 245 what percent of team b's mean absolute deviation is the difference in the means? 9% 15% 25% 65%

Which number completes the inequality? 2/3 < _ < 7/9