Word Problem

Question

Eight ounces of a health shake provide 2 grams of protein. How many ounces of the product would be
needed to provide 30 grams of protein?
[A] 120 oz [B] 117 oz [C] 122 oz [D] 119 oz

Answer 1

set up a proportion

8 oz/2 gm=n oz/30 gm

30/2=15 so 8*15=120 oz [A]

or....

2*n=8*30

2n=240

n=120 oz

or...

8 oz/2 gm=4 oz/1 gm

4 oz provides 1 gram

4*30=120 oz

Answer 2

Chris

 

Always best to use easier numbers first so you are sure whether to multiply or divide.  What if they asked you how many ounces you needed to provide 4 grams of protein?  For 2 grams you need 8 ounces so it is easy to see that for 4 grams you need twice, so 16 ounces.  2 grams times 2 = 4, and 2 times 8 ounces = 16 ounces, the multiplier is 2.  In this case 2 grams times what number gives you 30?  Or 30 divided by 2 is?  15, easy, so 15 is the multiplier.  15 times 8 is 120 and that is the answer.

 

Another approach is this way:

 

2 is to 8 as 30 is to X (some number) and we set that up as an algebraic formula and solve:

 

2/8 = 30/x  now cross multiply

 

2x = 240

 

x = 120

 

All the best

 

Lori 

Answer 3

2g/8oz. = 30g/X 

 

2x = 240 

 

x = 120oz.