Question 1.
Example: P=20000 Rs. , r= 10%. t= 2 years, A=?
Solution:
Question 2.
Example: What will be the compound interest on Rs. 12000 after 3 years at the rate of 10% per annum?
Solution:
Example: A sum of money becomes double itself in 5 years at compound interest. In how many years will it become 8 times of itself?
Solution:
Example:
Solution:
Convert r% into fraction (a/b)
Example: A man borrowed Rs.8,400 at 10% p.a. CI. He pays equal annual instalment and clear off his debts in 2 yrs. Find the instalment?
Solution:
Convert r% into fraction (a/b)
Example: A man borrowed Rs.397950 at 6% p.a. CI. He pays equal annual instalment and clear off his debts in 3 yrs. Find the instalment.
Solution:
Example: If the difference between S.I. and C.I. for 2 years on certain money is 4 Rs. The rate of interest is 8% per annum then find the money.
Solution:
Example: If the difference between S.I. and C.I. for 3 years on certain money is 31 Rs. The rate of interest is 10% per annum then find the money.
Solution:
Solution:
Solution:
Question 3.
If a sum of money becomes n1 times itself at compound interest in t1 years then after t2 sum will be:
Example: A sum of money becomes double itself in 5 years at compound interest. In how many years will it become 8 times of itself?
Solution:
Question 4.
Example:
Solution:
Question 5.
Calculation of instalment for 2 years:Convert r% into fraction (a/b)
Example: A man borrowed Rs.8,400 at 10% p.a. CI. He pays equal annual instalment and clear off his debts in 2 yrs. Find the instalment?
Solution:
Question 6.
Calculation of instalment for 3 years:Convert r% into fraction (a/b)
Example: A man borrowed Rs.397950 at 6% p.a. CI. He pays equal annual instalment and clear off his debts in 3 yrs. Find the instalment.
Solution:
Question 7.
If the difference between C.I. and S.I. for 2 years is given, then Principal:
Example: If the difference between S.I. and C.I. for 2 years on certain money is 4 Rs. The rate of interest is 8% per annum then find the money.
Solution:
Question 8.
If difference between C.I. and S.I. for 3 years is given, then Principal:
Example: If the difference between S.I. and C.I. for 3 years on certain money is 31 Rs. The rate of interest is 10% per annum then find the money.
Solution:
Question 9.
A sum of money invested at compound interest amounts to 800Rs. in 3 years and Rs. 882 in 5 years. What is the rate of interest?Solution:
Question 10.
When r% is given p.a. and CI has to be calculated half-yearly or quarterly basis:| Yearly | factors | r% (per annum) | Time (n years) |
|---|---|---|---|
| Half yearly | 6 months= (6/12)=1/2 |
Factor ×r%= r/2% | 2n |
| Quarterly | 3 months= (3/12)=1/4 | 1/4 ×r% = r/4% | 4n |
| 9 months | 9 months= (9/12)=3/4 | 3/4× r%= 3r/4% | 4n/3 |
| 8 months | 8 months= (8/12)= 2/3 | 2/3× r%= 2r/3% | 3n/2 |
