Answer:
15 days
Explanation:
since hair grows 0.3mm each day and we want to see how many days it will take the hair to grow to 16.5mm if the hair is already 12mm, let the time it takes (in days) for the hair to grow be x.
Subtract 16.5 from the hairs current length of 12
x=(16.5-12)÷0.3
Once you have done this, divide the answer by 0.3
x=4.5÷0.3
You are left with 15. It will take 15 days for the hair to grow to 16.5mm if it is 12mm.
x=15