To add any fraction You need to make sure that the denominator of the fractions are same. ( denominator in your sum is 19 )
10/19 + 3/19 ( we have the same denominator )
we can also write this problem like
( 10 + 3 ) / 19 { add the numerators together }
13 / 19
So correct option is B.
hope this helped.. :)
Answer:

Step-by-step explanation:
Given data for the cone
height h= 4 in
radius r= 1 in
hence diameter d= 2 in
thickness of cone= 0.1 in
The volume of the cone including the shell can be expressed as


The volume of the ice cream can be expressed as
N/B: the diameter of the ice cream is
2-(0.1*2)= 2-0.2= 1.8 in
hence the radius is 0.9 in

The difference in volume is 
Answer:
At a price of $p, a quantity, q, of the item is sold.
If q = f(p)
(a) f(150) = 2000 means at price = 150$, the number of items sold is 2000
(b) f'(150) = -25 means rate of sale is negative or the number of items sold will be decreases in future