Answer: 226 grams
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Step-by-step explanation:
1/2 = 0.5
Every 60 days, the amount cuts in half.
We start with 904 grams and after 60 days, we have 904*0.5 = 452 grams left over.
After another 60 days, we have 452*0.5 = 226 grams left over.
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Alternative Method:
We can apply the half-life formula.
y = a*(0.5)^(x/H)
where,
- y = final amount after x days
- a = initial amount
- x = number of days that elapse
- H = number of days in a half-life
In this case,
- a = 904 is the starting amount
- H = 60 is the number of days until another half-life occurs
When x = 120 days go by, we have....
y = a*(0.5)^(x/H)
y = 904*(0.5)^(x/60)
y = 904*(0.5)^(120/60)
y = 904*(0.5)^(2)
y = 904*(0.25)
y = 226 grams of antimony left over.
This method is preferred over the first method if you have x be some non-multiple of 60, or if x is fairly large.