This Is a Certified Answer

Certified answers contain reliable, trustworthy information vouched for by a hand-picked team of experts. Brainly has millions of high quality answers, all of them carefully moderated by our most trusted community members, but certified answers are the finest of the finest.
Lets represent:
x=missing gram

31 g+328 g+x+159 g=1,000 g
Add like terms
x+518 g=1,000 g
Subtract both sides by 518 g
x=482 g

Hope this helps =)