SPEAKER EUGENIO PEREZ NATIONAL AGRICULTURAL HIGHSCHOOL
San Carlos City, Pangasinan
GENERAL MATHEMATICS
2nd Quarter Module 1
Simple and Compound Interest
Identify what is being asked in the following given problems. Write your answers and solutions in a clean piece of paper.
Encircle your final answer.
Simple Interest Compound Interest
for Simple Interest (
Is¿
:
Is=Prt
where:
I
s
– Simple Interest (in monetary unit)
P
– Principal Amount (in monetary unit)
r
– rate (in percent)
t
− time (in year or annually)
for Compound Interest (
Ic¿
:
Ic=Fc−P
where:
I
c
– Compound Interest (in monetary unit)
F
c
– Future or Maturity Value (in monetary
unit)
P
– Principal Amount (in monetary unit)
for Future or Maturity Value
(F¿¿ s)¿
:
Fs=Is+P
where:
Fs
– Future or maturity value (in
monetary unit)
I
s
– Simple Interest (in monetary unit)
P
– Principal Amount (in monetary unit)
for Future or Maturity Value
(F¿¿ C)¿
:
Fc=P(1+r)t
where:
F
c
– Future or Maturity value (in monetary
unit)
P
– Principal Amount (in monetary unit)
r
– rate (in percent)
t
− time (in year or annually)
1) Given the above formula for Simple Interest, DERIVE a formula for the following unknowns: (5points each)
a)
r
b)
t
c)
Fs
2) Given the above formula for Compound Interest, DERIVE a formula for the following unknowns: (5points each)
a)
P
b)
r
c)
t
EXAMPLE: Derive a formula when
P
is unknown in simple interest.
Solution:
Step1: Using
Is=Prt
Step 2: Divide both side by
rt
Is
rt =Prt
rt
Step 3: Since
rt
rt
is equal to 1
Is
rt =Prt
rt
Step 4: Therefore
Is
rt =P
Step 5: Answer
P=Is
rt
