To find the total amount Mrs. Johnson gave away, you need to know how much she gave the son. Because the ratio of the money given is 5:6, the amount of money he received has to be 5/6 of the money the daughter received.
So, the son received 5/6 of 2400.
To find this, multiply 5/6 x 2400 to get 2000.
The daughter received 2400 and the son received 2000, so the total amount Mrs. Johnson gave away is 4400 dollars.
The person would have to leave the money in the bank for 7.8 years for it to reach 13,500 dollars.
Step-by-step explanation:
Step 1; First we must calculate how much interest is generated for a single year. The annual interest rate is 4.5% i.e. 4.5% of 10,000 dollars which equals 0.045 × 10,000 = 450 dollars a year. As the years pass, more and more will be put into the account due to interest.
Step 2; For there to be 13,500 dollars in the bank account we need to calculate how much money is added due to interest.
The money needed to be added through interest = 13,500 - 10,000 = 3,500 dollars.
So we need to determine how long it will take for the bank to add 3,500 dollars by adding 450 dollars a year.
The number of years to reach 13,500 dollars = = 7.777 years. By rounding this value to the nearest tenth, we get 7.8 years.
Continuous compounding is the mathematical limit that compound interest can reach.
It is the limit of the function A(1 + 1/n) ^ n as n approaches infinity. IN theory interest is added to the initial amount A every infinitesimally small instant.
The limit of (1 + 1/n)^n is the number e ( = 2.718281828 to 9 dec places).
Say we invest $1000 at daily compounding at yearly interest of 2 %. After 1 year the $1000 will increase to:-
1000 ( 1 + 0.02/365)^365 = $1020.20
with continuous compounding this will be
1000 * e^1 = $2718.28