at what rate of simple interest will a sum of money double itself in four year ?
think about it. In 4 years you have added 100%
So, that's 25% per year.
8.Mary invested RM3000 in two accounts, some at 12% per annum and the rest at 8 percent per annum.Her total interest for one year was RM3200.how much was invested at each rate?
.12x + .08(3000-x) = 3200
now just solve for x, the amount at 12%
I can tell you right now that there's a typo in there somewhere.
How long will it take for a sum of rs 12600 invested at 9 % per annum becomes to 15678
in5yr Rs/-5000 amounts to Rs/-9000. in what time at the same rate will rs/- 600 amounts to Rs- 900
To find the rate of simple interest at which a sum of money will double itself in four years, we need to use the formula:
Simple Interest = (Principal * Rate * Time) / 100
Let's assume the principal amount is P, and the rate of interest is R. We are given that the sum of money will double in four years, which means the amount after four years will be twice the principal amount.
Using this information, we can set up the equation:
2P = P + (P * R * 4) / 100
The left side of the equation represents the amount after four years, which is twice the principal amount. On the right side, the first "P" is the initial principal amount, and the second term represents the simple interest earned over four years. We divide by 100 to convert the rate from a percentage to a decimal.
Now, let's solve the equation to find the value of the rate (R):
2P = P + (P * R * 4) / 100
Multiplying both sides by 100 to remove the fraction:
200P = 100P + 4P * R
Simplifying the equation:
200P - 100P = 4P * R
100P = 4P * R
Cancelling out P on both sides:
100 = 4R
Dividing both sides by 4:
25 = R
Therefore, the rate of simple interest required for the sum of money to double itself in four years is 25%.