Answer:
The portion of the volume of the cup that is filled with water is 
Step-by-step explanation:
step 1
Find the volume of the paper water cup
The volume of the cone is equal to

we have


substitute


step 2
If the cup is filled with water to half its height, find out what portion of the volume of the cup is filled with water
Remember that
If two figures are similar, then the ratio of its volumes is equal to the scale factor elevated to the cube
In this problem the similar cone has half the height of the complete cone
so
The scale factor is equal to 1/2
therefore
The volume of the cup that is filled with water is equal to the volume of the complete cup by the scale factor elevated to the cube

therefore
The portion of the volume of the cup that is filled with water is

Find percent -> 2nd month.
4264*.25==1066 phone calls+=4264
==5330 for 2nd month.
for 2nd -> 3rd
6396==5330*x, solve algebraically to get .20 == 20% increase from 2nd month to 3rd month.
Answer: Its surface covers 1400 cm²
Explanation:
Since the length of painting = 40 cm
Breadth of painting = 35 cm
Since we know that area of rectangle is product of dimensions.
∴ Area of painting = length × breadth
= 40 cm × 35 cm
= 1400 cm²
∴ Its surface cover 1400 cm².