১.
If the ratio of principal and the simple interest of 5 year is 10:3, then the rate of interest is = ?
ব্যাখ্যা
P/S.I.=10/3
Let Principal = 10
S.I. for 5 year = 3
S.I. for 1 year = 0.6
Rate = S.I./Principal×100
Rate = 0.6/10×100
=6%
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Simple & Compound Interest, Problems on Ages [ব্যাংকের সকল পরীক্ষা যেকোনো প্যাকেজের জন্য ফ্রি]
ব্যাংক নিয়োগ প্রস্তুতি ⎯ লং কোর্স
ব্যাংক নিয়োগ প্রস্তুতি ⎯ লং কোর্স · তারিখ অনির্ধারিত · ২৭ প্রশ্ন
২.
A sum of money at simple interest amounts to Tk. 815 in 3 year and to Tk. 854 in 4 year. The sum is
ব্যাখ্যা
S.I. for 1 year=Tk.(854−815)=Tk.39
S.I. for 3 year=Tk.(39×3)=Tk. 117
∴Principal=Tk.(854−117)=Tk. 698
৩.
A sum of Tk. 12,500 amounts to Tk. 15,500 in 4 year at the rate of simple interest. What is the rate of interest?
ব্যাখ্যা
S.I.=Tk.(15500−12500)=Tk.3000
Rate=(100×3000)/(12500×4)%= 6%
৪.
A simple interest earned on certain amount is triple the money when invested for 16 year.what is the interest rate offered?
ব্যাখ্যা
Given,
S.I = 3 Principal Amount
=> 3A = A x 16 x R/100
By solving, we get
=> R = 18.75%
৫.
The present of Tk.169 due in 2year at 4% per annum compound interest is
ব্যাখ্যা
Present worth = 169/(1+4/100)^n = 156.25
৬.
A person lends Tk. 1540 for five year and Tk. 1800 for four year. If he gets Tk. 1788 as interest on both amounts, what is the rate of interest?
ব্যাখ্যা
Let the interest rate be r%
We know that,
S.I = PTR/100
=> (1540 x 5 x r)/100 + (1800 x 4 x r)/100 = 1788
=> r = 178800/14900 = 12%
৭.
A person takes a loan of Tk. 200 at 5% simple interest. He returns Tk.100 at the end of one year. In order clear his dues at the end of 2 year, he would pay :
ব্যাখ্যা
Amount to be paid = Tk.[100+(200×5×1)/100+(100×5×1)/100] = Tk. 115.
৮.
The difference between the simple interest received from two different sources on Tk.1500 for 3 year is Tk.13.50. The difference between their rates of interest is
ব্যাখ্যা
(1500 x R1 x 3)/100
=> 4500 (R1-R2) = 1350
=> (R1-R2)= 1350/4500 = 0.3 %
৯.
A certain amount earns simple interest of Tk. 1750 after 7 year. Had the interest been 2% more, how much more interest would it have earned?
ব্যাখ্যা
We need to know the S.I, principal and time to find the rate. Since the principal is not given, so data is inadequate.
১০.
The compound interest on a certain sum for 2 year at 10% per annum is Tk. 525. The simple interest on the same sum for double the time at half the rate percent per annum is
ব্যাখ্যা
Let the sum be Tk. P.
Then,[p(1+10/100)2-p]=525
Sum =Tk.2500
S.I.= Tk.(2500×5×4)/100
= Tk. 500
১১.
The compound interest on Tk.30000 at 7% per annum is Tk.4347. The period is
ব্যাখ্যা
Amount = Tk.(30000+4347) = Tk.34347
let the time be n year
Then,
30000(1+7/100)n = 34347
(107/100)n = 34347/30000 = 11449/10000 = (107/100)2
n = 2year
১২.
A sum of money amounts to Tk.6690 after 3 year and to Tk.10,035 after 6 year on compound interest.find the sum.
ব্যাখ্যা
Let the sum be Tk.P.then
P(1+R/100)3=6690…(i) and
P(1+R/100)6=10035…(ii)
On dividing,we get (1+R/100)3=10025/6690=3/2.
Substituting this value in (i),we get:
P×(3/2)=6690 or
P=(6690× 2/3)=4460
Hence,the sum is Tk.4460.
১৩.
A sum of money lent at compound interest for 2 year at 20% per annum would fetch Tk.482 more, if the interest was payable half yearly than if it was payable annually. The sum is
ব্যাখ্যা
Let sum=Tk.x
C.I. when compounded half yearly = [x(1+10/100)4−x]=4641/10000
C.I. when compounded annually =[x(20/100)2−x]=11/25
4641/10000x−11/25x=482
=> x=20000
১৪.
Find compound interest on Tk. 8000 at 15% per annum for 2 year 4 months, compounded annually
ব্যাখ্যা
Time = 2 year 4 months = 2(4/12) year = 2(1/3) year.
Amount = Tk'. [8000 X (1+(15/100))2 X (1+((1/3)×15)/100)]
=Tk. [8000 ×(23/20) × (23/20) ×(21/20)]
= Tk. 11109.
:. C.I. = Tk. (11109 - 8000)
= Tk. 3109.
১৫.
Rajeev's age after 15 year will be 5 times his age 5 year back. What is the present age of rajeev?
ব্যাখ্যা
Let Rajeev's present age be x year.
Rajeev's age after 15 year = (x + 15) year.
Rajeev's age 5 year back = (x - 5) year
Then ATQ,
x + 15 = 5 (x - 5)
x + 15 = 5x - 25
=> x = 10
Hence, Rajeev's present age = x = 10 year.
১৬.
A person's present age is two-fifth of the age of his mother. After 8 year, he will be one-half of the age of his mother. How old is the mother at present?
ব্যাখ্যা
Let the mother's present age be x year.
Then, the person's present age = 2/5 x year.
(2x/5 + 8) = 1/2 (x + 8)
2(2x + 40) = 5(x + 8)
=> x = 40.
১৭.
The ages of X and Y are in the proportion of 6:5 and total of their ages is 44 year. The proportion of their ages after 8 year will be
ব্যাখ্যা
Let current ages of X and Y correspondingly, is 6A & 5A
Given: 6A + 5A = 44
=> A = 4
Proportion of ages after 0.8 decades will be
6A + 8 : 5A + 8
32:28 (or) 8:7
১৮.
The average age of a class is 15.8 year. The average age of the boys in the class is 16.4 year and that of the girls is 15.4 year. What is the ratio of boys to girls in the class?
ব্যাখ্যা
Let number of boys = x,
Let number of girls = y
Total numbeTk of students = x + y
(x + y) × 15.8 = 16.4x + 15.4y
0.6x = 0.4y
x/y = 0.4/0.6 = 2/3
Ratio of boys and girls in the class is 2:3
১৯.
Ten year ago A was half of B in age. If the ratio of their present ages is 3 : 4, what will be the total of their present ages
ব্যাখ্যা
Let A's age 10 year ago = x year.
Then, B's age 10 year ago = 2x year.
(x + 10) / (2x+ 10) = 3/4
=> x = 5.
So, the total of their present ages
=(x + 10 + 2x + 10)
= (3x + 20)
= 35 year.
২০.
If Riya's age is four times the age of Siya and if Riya's age is 24 years, find the age difference between Riya and Siya?
ব্যাখ্যা
Let Siya's age = x
Then Riya's age = 4x
But given Riya's age = 24
=> 4x = 24
=> x = 6
Hence Siya's age = 6 years
=> The age difference = 24 - 6 = 18 years.
২১.
A is two year older than B who is twice as old as C. If the total of the ages of A, B and C be 27, then how old is B?
ব্যাখ্যা
Let C's age be x year.
Then, B's age = 2x year.
A's age = (2x + 2) year.
(2x + 2) + 2x + x = 27
5x = 25
=> x = 5
Hence, B's age = 2x = 10 year.
২২.
5 year ago Sushma was 5 times as old as her Son. 5 year hence her age will be 8 less than three times the corresponding age of her Son. Find their ages?
ব্যাখ্যা
Let the age of sushma be x and
the age of her son is y
Then five year before x-5=5(y-5) ...(1)
Five year hence x+5 = 3(y+5)-8 .....(2)
By soving (1) & (2), we get
5y - 15 = 3y + 7
y = 11
=> x = 35
Therefore, the age of Sushma = 35 and her son = 11.
২৩.
The sum of the ages of 5 children born at the intervals of 3 year each is 50 year. What is the age of the youngest child?
ব্যাখ্যা
Let the age of the youngest child is 'X' year.
Then the child elder than the yongest is 'X + 3' years
Since each have 3years difference upto 5 children
And given that
=> X + X+3 + X+6 + X+9 + X+12 = 50
=> 5X + 30 = 50
=> X = 4 years.
২৪.
The twice of sum of the ages of a father and his son is 8 times the age of the son. If the average age of the father and the son is 30 year, what is father's age?
ব্যাখ্যা
Let father's age be x year and son's age be y year.
According to question,
2(x+y) = 8y _______(I)
and (x+y)/2 = 30
=> x+y = 60 year_______(II)
From equation (I) and (II)
8y = 120
y = 15 year,
Hence x = 45 year.
২৫.
The average age of husband, wife and their child 3 year ago was 24 year and that of wife and child 5 year ago was 25 year. The present age of the husband is:
ব্যাখ্যা
Sum of ages of husband, wife and child= (24 × 3) + 9 = 81 year
Sum of ages of wife and child
=> 25 × 2 + 10 = 50 + 10 = 60 year
Age of husband = 81 - 60 = 21 year
২৬.
The average age of 8 men is increased by 4 year when one of them whose age is 30 year is replaced by a new man. What is the age of new man?
ব্যাখ্যা
Let the average of 8 men be x.
Age of new man be N.
Total age of 8 men = 8x
⇒ x + 4 = ((8x – 30) + N)/8
⇒ 8x + 32 = 8x – 30 + N
⇒ N = 32 + 30
⇒ N = 62
২৭.
When I was 24, my mother was twice my age. Now I am 44, how old is my mother?
ব্যাখ্যা
From the given data,
when my age is 24, my mothers age is double of my age
=> 48 years is my mothers age
=> Difference is 48 - 24 = 24 year.
When my age is 44
=> My mother is 44 + 24 = 68 year aged.