Answer:
[tex]\boxed{6.875 \text{\: grams}}[/tex]
Step-by-step explanation:
Half-lives are how long it takes for half of a substance to decay. If you start with a certain amount and it decays for a certain amount of half-lives, you are dividing by [tex]2^{x}[/tex], where x is equal to the amount of half-lives.
In order to solve this question, simply divide the starting value by 2 raised to the value of half-lives.
[tex]\large\boxed{\frac{220}{2^{5}}=6.875\text{\: grams}}[/tex]
