15.12 grams of sugar was how much he drank. Or round it down and it becomes 15.
Explanation:
Turn 3 3/5 into an improper fraction = 18/5 x 3 full bottles. In order to multiply 18/5 with 3 turn it into a decimal form.
18/5 = 3.6 x 3 full bottles = 10.8 sugar in 3 bottles.
Now find 2/5 of that. 10.8 divided by 5 = 2.16 x 2 = 4.32.
10.80+4.32= 15.12 grams of sugar he drank.
