Question

Through research scientists found that the body or a 200 lb person consist of 3.2*10 to the nigetive five lbs of zinc. In the bodies on 1500 such people, how much zinc is present?
"Should i divide or add???"

Answer 1

In 1500 people of 200 lb each, the total weight would be 300000 lb.
Set up a proportion: 200lb/3.2*10^-5 = 300,000lb/x
(3.2*10^-5*300,000)/200 = x
x = 0.48, I believe