Numerator is the the number above the line on a fraction, while the denominator is the number underneath the line.

is similar to

Fraction with numerator -6 and denominator 8
Answer:
→[ Certain shade=red paint+ white paint]
→3 cups of red paint=7 cups of white paint
Dividing both side by 7,we get
→ 1 cup of white paint=3/7 cups of white paint
So, 3/7 of a cup should be added to 1 cup of white paint to make certain kind of shape.
Cups of white paint: Cups of red paint= 1. : 
k=
is constant of proportionality.