Question 22844
1. Convert the 3/8 gr. to 0.375 gr. by dividing 3 by 8
Now divide 0.375 gr. by 0.0125 gr  to get 30 doses.
2. Set up a propotion as follows:
  x/475 = 11.5/1000
     x = 475(11.5)/1000
     x = 5.46 gr. of anti histamine to make 475 tablets.
3.Again, set up a proportion as follows:
    x/ 1.2 ml  = 28 mg/ 3 ml
    x  = 1.2(28)/3)
    x  = 11.2 mg

Cheers,
stan H.