Tips for the 1st & 2nd missions...

Mission 1 - start the game with 5 of each flavor and see which is most liked and purchase those, raise your prices to 50. Once you reach a rating of 3% raise your prices to 60 or 70. Once you reach 7% rating raise them again to 80 or 90. Monitor your flavors all the time. This should raise you to the 10% rating without going broke.

Mission 2 - Try to raise your rating as much as possible before hitting your goal here...as this is not difficult. To reach your goal simply raise your prices to 300 and purchase the most expensive ice creams( the newly unlocked ones) and alternate between the most populated area.