If you can buy 4⁄5 of a pound of ham for 3 dollars, how much can you purchase for 10 dollars? write your answer as a fraction of a pound.

It is very important to minutely look at all the details provided in the question. Based on those information's the answer to the question can be easily solved.
The amount of ham that can be bought for 3 dollars = 4/5 pounds
Then
The amount of ham that can be bought for 10 dollars = [(4/5)/3] * 10 pounds
                                                                                      = (4 * 10)/15 pounds
                                                                                       = 40/15 pounds
                                                                                       = 8/3 pounds
                                                                                       = 2 2/3 pounds
So the quantity of ham that can be purchased for 10 dollars is 2 2/3 pounds. I hope the procedure is simple enough for you to understand.You can always use this method for
solving similar type of problems without requiring any kind of help from outside.