Question 1: The height of a plant is and it is expected to grow at the rate of
every month. What will be its height at the end of
?
Answer:
Question 2: The cost of a machine is supposed to depreciate each year by of its value at the beginning of the year. If the machine is valued at
at the beginning of
, find its value:
- At the end of
- At the beginning of
Answer:
At the end of
At the beginning of
Question 3: The value of a machine is estimated to be at the end of
and
at the beginning of
. Supposing it depreciates at a constant rate per year of its value at the beginning of the year, calculate:
- The rate of depreciation;
- The value of the machine at the beginning of
.
Answer:
At the end of
At the beginning of
Question 4: The value of in article decreased for two years at the rate of per year and then in the third year it increased by
. Find the original value of the article, if its value at the end of
is
.
Answer:
At the end of
At the end of
Question 5: According to a census taken towards the end of the year , the population of a rural town was found to be
. The census authority also found that the population of this particular town had a growth of
per annum. In how many years after
did the population of this town reach
?
Answer:
At the end of
Question 6: The population of a town decreased by during
and then increased by
during
. Find the population of the town, at the beginning of
, if at the end of
its population was
.
Answer:
At the end of
At the beginning of
Question 7: A sum of money, invested at compound interest, amounts to in
and to
in
. Find the rate per cent and the original sum of money.
Answer:
Question 8: The difference between C.I. and S.I. on for two years is
at the same rate of interest per annum. Find the rate of interest.
Answer:
Simple Interest
Compound Interest
Question 9: A sum of money lent out at C.I. at a certain rate per annum becomes three times of itself in . Find in how many years will the money become twenty-seven times of itself of the same rate of interest p.a.
Answer:
After 10 Years
After n Years
Substituting from i)
Question 10: Sharma borrowed a certain sum of money at per annum compounded annually. If by paying
at the end of the second year and
at the end of the third he clears the debt; find the sum borrowed by him.
Answer:
Third year
Question 11: The difference between compound interest for a year payable half-yearly and simple interest on a certain sum of money lent out at for a year is
. Find the sum of money lent out. [1998]
Answer:
Simple Interest
Compound Interest
Question 12: The ages of Person 1 and Person 2 are and
respectively. In what ratio must they invest money at
p.a. compounded yearly so that both get the same sum on attaining the age of
?
Answer:
Person 1:
Person 2: