Rosy lent out a certain sum. She lent 1/3rd part of it at 7% SI, 1/4th part at 8% SI and remaining part at 10% SI. If Rs.510 is her total interest after one year, find the total money lent out.
An automobile financier claims to be lending money at simple interest, but he includes the interest every six months for calculating the principal. If he is charging an interest of 10%, the effective rate of interest becomes:
Simple interest is given by the formula SI = (pnr/100), where p is the principal, n is the number of years for which it is invested, r is the rate of interest per annum
In this case, Rs. 1250 has become Rs.10,000.
Therefore, the interest earned = 10,000 – 1250 = 8750.
8750 = [(1250 x n x 12.5)/100]
=> n = 700 / 12.5 = 56 years.
Workspace
A person borrows Rs. 5000 for 2 years at 4% p.a. simple interest. He immediately lends it to another person at 6p.a for 2 years. Find his gain in the transaction per year.
Abhay gave Rs 1200 on loan. Some amount he gave at 4% per annum on simple interest and remaining at 5% per annum on simple interest. After 2 years he got Rs 110 as interest. Then the amounts given at 4% and 5% per annum simple interest are respectively.
Let rate is R%.
Now,
P = 100;
A = 400;
I = 400-100 = 300;
Time, T = 10 years;
I = PTR/100;
Or, R = (100*I)/PT;
Or, R = (100*300)/(100*10);
Hence, R = 30%;
2nd Method:
Here, the sum becomes 4 times that means 100, become 400;
Rate of such question is given by;
R= interest/time = 300/10 = 30%;
3rd Method:
Here, 300% of rise in the sum,so
100——300%↑—-400;
R=(total percentage rise/given time) = 300% /10 = 30%.
Workspace
What will be the ratio of simple interest earned by certain amount at the same rate of interest for 6 years and that for 9 years?
