mixed powder ratios in a bag

Question

If you have 57 grams of substance A and 19 grams of substance B and 19 grams of substance C and 15 grams of substance D and 9 grams of substance E and you mix all of these powders perfectly in a bag and you then take a 4 gram serving size out of the already mixed bag how much of each substance would you have in milligrams of each substance from the 4 gram serving size?

Answer 1

57 milligrams in substance A

19 in B

19 C

15 D

9 E

mix them all up and take a 4 gram sample

how much of each substance do you have in the sample

1 gram = 1000 milligrams

4 grams = 4,000 mg

57+19+19+15+9 = 119 mg

It's impossible to take a 4 gram sample out of only 119 mg. You can't get blood out of a turnip

there's a problem with the problem. maybe a typo misprint or mis-copied

Answer 2

Sum up the weights of each substance. Call that w

Multiply each substance's weight by (4 / w)