1. At 12.5%
simple rate of interest , in how many years the principal amount will be four
times with interest.
Answer: Let
the principal amount is Tk. 100
so,
principal amount with interest = 100 ×
4 = Tk. 400
So, interest
= 400-100 = Tk. 300
At 12.5%
interest or, 25/2% interest ,
Tk. 25/2
comes from 1 year
1 comes from
2/25 year
300 comes
from =(2×300)/25 = 24 Years.
2. The
monthly salary of a person increased by 10% in one month, but is decreased by
10% in the next month. What is the percentage increase or decrease in his
original salary?
Answer: Let,
salary of the person is Tk. 100
So, At
increase of 10% salary = 100 ×
(1 × 0.1) = Tk. 110
Again, at a
decrease of 10% salary = 110 ×
(1-0.1) = Tk. 99
So, Decrease
in his original salary = (100-99) = Tk. 1
Percentage
decrease of his original salary = 1%
3. Give the
name of the countries to which the following Airlines?
1. Garuda 2.
Lutfthansa 3. Airlanka
Answer:
Garuda - Indonesia, Lutfthansa - Germany , Airlanka- Srilanka
