For the fraction 28/10,
times 10 at 28 and 10,(to get the same denominator"100")
28×10=280
10×10=100
Thus,
28/10 become 280/100
We can plus the number above the denominator"100",which is 39 and 280.It is because they have achieved a same denominator.
39/100+280/100
=(39+280)/100
=319/100
If you add them both together you will get 2150. 2000+150=2150
Answer: Choice D
b greater-than 3 and StartFraction 2 over 15 EndFraction
In other words,
b > 3 & 2/15
or

========================================================
Explanation:
Let's convert the mixed number 2 & 3/5 into an improper fraction.
We'll use the rule
a & b/c = (a*c + b)/c
In this case, a = 2, b = 3, c = 5
So,
a & b/c = (a*c + b)/c
2 & 3/5 = (2*5 + 3)/5
2 & 3/5 = (10 + 3)/5
2 & 3/5 = 13/5
The inequality
is the same as 
---------------------
Let's multiply both sides by 15 to clear out the fractions

---------------------
Now isolate the variable b

Side note: Another way to go from 47/15 to 3 & 2/15 is to notice how
47/15 = 3 remainder 2
The 3 is the whole part while 2 helps form the fractional part. The denominator stays at 15 the whole time.
The answer is E I did a test like this before and they try to trick you