Answer: 6.93 years
Step-by-step explanation:
Given
Rate of interest is 
Future value is given by 
For the investment to double itself, i.e. 

It takes around 6.93 years to double the investment.
Answer:
Step-by-step explanation:
Let x represent the number of units of games sold.
The inventor of a new game believes that the variable cost for producing the game is $0.90 per unit and the fixed costs are $6200. It means that the total variable cost for x units would be
0.9 × x = 0.9x
The inventor sells each game for $1.69. This means that the total revenue from x units of games sold would be
1.69 × x = 1.69x
The total cost for a business is the sum of the variable cost and the fixed costs. Therefore, the total cost for the number of games sold would be
C = 6200 + 0.9x
Profit = Revenue - total cost
Therefore,
Profit = 1.69x - (6200 + 0.9x)
= 1.69x - 0.9x - 6200
= 0.79x - 6200
Answer:
Twenty divided by four equals five.
Answer:

So it would takes approximately 6.9 hours to reach 32 F.
Step-by-step explanation:
For this case we have the following differential equationÑ

We can reorder the expression like this:

We can use the substitution
and
so then we have:

IF we integrate both sides we got:

If we apply exponential in both sides we got:

And if we replace w = u-T we got:

We can also express the solution in the following terms:

For this case we know that
since w ehave a cooloing,
, we have this model:
And if we want that the temperature would be 32F we can solve for t like this:



If we apply natural logs on both sides we got:


So it would takes approximately 6.9 hours to reach 32 F.