Answer:
The answer is 24
Step-by-step explanation:
The total amount of phone covers were 200.
35% of those were black. So, 200 x 35% (or 200 x .35) = 70.
70 of the phone covers sold were black.
23% of the covers were blue. So, 200 x 23% (or 200 x .23) = 46
46 of the phone covers sold were blue.
How many more black covers sold than blue covers means we subtract.
70 black covers - 46 blue covers = 24 more black covers sold.