Question

A jar holds 128 fluid ounces of juice. The label says the jar has 16 servings. How many fluid ounces are needed for 80 servings?

Answer 1

There are 16 servings for each 128 fluid ounces of juice. 

Divide 80 servings by 16 servings, and 5 should be the quotient. Therefore, there are 5 jars of juice. Multiply 128 by 5 since 128 fluid ounces are in one jar. The answer should be 640 fluid ounces. 

Answer 2

Answer: 640 fluid ounces

Step-by-step explanation:

We assume that the fluid ounces in jar is directly proportional to the number of servings.

Given : A jar holds 128 fluid ounces of juice. The label says the jar has 16 servings.

Ratio of  fluid ounces of juice to number of servings =$\dfrac{128}{16}$  (1)

Let x denotes the fluid ounces are needed for 80 servings.

Ratio of  fluid ounces of juice to number of servings =$\dfrac{x}{80}$   (2)

From (1) and (2) , we have

$\dfrac{x}{80}=\dfrac{128}{16}$   [in direct variation ration  remains constant.]

$x=\dfrac{128\times80}{16}=640$

Hence, 640 fluid ounces are needed for 80 servings.