In order to get a certain shade of blue paint, a mixer must have 5 parts white paint to 3 parts blue. if 4 gallons of paint must be mixed, how many gallons of white paint must be used? 3.7 gallons 2.5 gallons 1.9 gallons 1.5 gallons

Option B. 2.5 gallons of white paint must be used

Step-by-step explanation:

In order to get a certain shade of blue paint, a mixer must have 5 parts white paint to 3 parts blue.

Total paint was mixed = 4 gallons.

5 parts white + 3 parts blue = 8 parts

divide it into 8 parts to get each part must be  = 4 ÷ 8 = 0.5 gallons

It is given that 5 parts of white paint = 5 × 0.5 = 2.5 gallons

and 3 parts of blue paint was mixed = 3 × 0.5 = 1.5 gallons

Option B. 2.5 gallons of white paint must be used.

2.5 gallons.

Step-by-step explanation:

Given : In order to get a certain shade of blue paint, a mixer must have 5 parts white paint to 3 parts blue.

Total paint mixed = 5+3= 8 parts

The ratio of white paint to the total mixture =

       (1)

Let x be the number of gallons of white paint.

If 4 gallons of paint must be mixed , then the  ratio of white paint to the total mixture =     (2)

From (1) and (2) , we have

Multiply 4 on both sides , we get

⇒ x= 2.5

⇒ Number of gallons of white paint is required = 2.5 gallons.