Answer:
2.2 grams
Step-by-step explanation:
We can use the compound decay formula shown below to solve this:

Where
F is the final amount (what we want to find)
P is the present amount (490 grams)
r is the rate of decay, in decimal (28.6% = 28.6/100 = 0.286)
t is the time in minutes (16)
Substituting, we get:

So, after 16 minutes, 2.2355 grams will be remaining.
<em>Rounded to nearest tenth of a gram (1 decimal place) = </em><em>2.2 grams remaining</em>
Answer:
The geometric mean of 14 and 20 is 16.73.
Step-by-step explanation:
It is required to find the geometric mean of 14 and 20. Let the numbers are :
a = 14 and b = 20
The geometric mean for two numbers is given by :

Plugging the values in above formula as follows :

So, the geometric mean of 14 and 20 is 16.73.
Answer:
n + 11 and 11 + n
Step-by-step explanation:
Let n be the unknown number,
n is increased by 11,
That is, n + 11
By the commutative property of addition,
The expression would be,
11 + n
For drawing a model that shows n + 11
Take two boxes in which first shows n and second shows 11 and add them,
Similarly, for showing 11 + n, take first box that shows 11 and second box that shows n then add them.
The collect 19 boxes by the end of everyday.