
Answer:
The answer to your question is 388 cans
Explanation:
Data
concentration of caffeine = 2.15 mg/oz
number of cans = ?
lethal dose = 10 g
caffeine in a can = 12 oz/can
Process
1.- Convert 10g to mg
        1000 mg ----------------- 1 g
           x      ----------------- 10g
         x = (10 x 1000)/1
         x = 10000 mg
2.- Calculate the numbers of oz in 10 g
         2.15 mg ---------------- 1 on
       10000 mg -------------- x
         x = (10000 x 1)/ 2.15
         x = 4651.2 oz
3.- Calculate the number of cans
        12 oz --------------- 1 can
      4651.2 oz --------------  x
        x = (4651.2 x 1)/12
        x = 387.6 ≈ 388 cans