Answer:
40 pounds
Step-by-step explanation:
Given: Cost of a candy =
per pound
Cost of candy
Total amount of mixture of be produced =
Selling price of mixture =
Let´s x be the amount of to be mixed in the mixture.
∴ Cost of in the mixture = 12x
Next, Cost of in the mixture =
And we know the cost of final mixture =
Now, putting all the value in the equation
⇒
⇒
⇒
∴
∴ 40 pounds of candy worth $12 per pound to be mixed in the mixture.
Answer:
According to the rule of 72, the doubling time for this interest rate is 8 years.
The exact doubling time of this amount is 8.04 years.
Step-by-step explanation:
Sometimes, the compound interest formula is quite complex to be solved, so the result can be estimated by the rule of 72.
By the rule of 72, we have that the doubling time D is given by:
The interest rate is in %.
In our exercise, the interest rate is 9%. So, by the rule of 72:
.
According to the rule of 72, the doubling time for this interest rate is 8 years.
Exact answer:
The exact answer is going to be found using the compound interest formula.
In which A is the amount of money, P is the principal(the initial sum of money), r is the interest rate(as a decimal value), n is the number of times that interest is compounded per unit t and t is the time the money is invested or borrowed for.
So, for this exercise, we have:
We want to find the doubling time, that is, the time in which the amount is double the initial amount, double the principal.
is double the initial amount, double the principal.
The interest is compounded anually, so
Now, we apply the following log propriety:
So:
The exact doubling time of this amount is 8.04 years.