1.Flight times for a certain airline are normally distributed with a mean of 3.25 hours and a standard deviation of 0.15 hours. Approximately what percentage of the flights last between 2.95 and 3.55 hours?

There's no way to tell. 

The AVERAGE number in each gourp is  (1,464/10) = 146.4 pennies.
But some gourps must have more and some must have less ... we know
that, because no gourp can have exactly 146.4 pennies without chopping
pennies up into pieces.