TK 50,000
Here, n = 3 , c = 66550 and r = 10% = $\frac{10}{100}$
P = ?
We Know, c = p $(1+\frac{10}{100})^{3}$
=> 66550 = p$(\frac{110}{100})^{3}$
=> p = $\frac{66550\cdot10\cdot10\cdot10}{11\cdot11\cdot11}$ = 50,000
Tk. 3439
At l0% less in 2nd year.
When Tk 100 less = Tk. 10
When TR 1000 less = Tk. $\frac{10\cdot100}{100}$
= Tk. 100
Insurance cost for 2nd year = 1000 — 100 = Tk 900
At 10% less in 3rd year.
When Tk. 100 then less = Tk. 10
When Tk. 900 less = Tk. $\frac{10\cdot90}{100}$
= Tk. 90
Insurance cost for 3rd year = Tk. 900 – 90
= Tk. 810
At 10% less in 4th year.
When Tk. 100 then less = Tk. 10
When Tk. 810 less = Tk. $\frac{10\cdot810}{100}$
= Tk. 81
Insurance cost for 4th year = 810 — 81 = Tk. 729
So total cost of insurance for first 4 year = 1000 + 900 + 810 + 729
= Tk. 3439
Tk. 83,280 and Tk. 1.06.920 respectively
A’s salary = Tk. 12.000
The rest of profit = 2.10.000 — 12,000
= Tk. 1.98.000
10% of 1.98.000 =$\frac{198000\cdot10}{100}$ = 19.800 Tk. (set aside)
Alter 10% set aside. the rest of profit = Tk. 1.98.000 — 19,800
= Tk. 1.78,200
Now, A : B = 4.00.000 : 6.00.000 = 2 : 3
Sum total ofratio = 2 + 3 = 5
A’s profit = 1.78.200 of $\frac{2}{5}$
= Tk. 71,2 80
8’5 profit = 1.78.200 of $\frac{2}{5}$
= Tk. 1.06.920
A receives = 71.280 + 12.000 = Tk. 83.280
B receives = Tk. 1.06.920
40 marksQ
Total marks of 100 students = 100 x 85 = 8500
The rest of students after 10% excluded = 90
So, the total marks of 90 students = 90 x 90 = 8100
Now, the total marks of 90 studcnts = 100 — 90 = 10
The total marks of excluded students = 8500 – 8100 = 400
So, the average mark of 10% excluded students = 400 + 10 = 40 marks.
(a) TK 63750
(b) TK 300000
For question no (a),
At 5% commission on sales,
Tk. 100 Makes commission = Tk. 5
Tk. 75,000 Makes commission = Tk. $\frac{5\cdot75000}{100}$
= Tk. 3750
For question no (b),
His total eaming = 60,000 + 3.750 = 63,750 Tk.
His commission = 75,000 — 60,000 = Tk. l5,000
Tk. 5 commission comes from = Tk. 100
Tk. 15,000 commission comes from = Tk. $\frac{100\cdot15000}{5}$
= Tk. 3,00,000
TK 80
At 12.5% loss, selling price = (100 — 12.5) Tk. = 87.5 Tk.
At 25% profit, selling price would be = (100 + 25) Tk. = 125 Tk.
Difference of selling price = (125 — 87.5) Tk. = 37.5 Tk.
Selling price Tk. 37.5 more when cost price = Tk. 100
Selling price Tk. 30 more when cost price =$\frac{100\cdot30}{37.5}$= 80 Tk.
18 minutes
For 30 km the car takes = 60 minutes
For 1 km the car takes =$\frac{60}{30}$minutes
= 2 minutes
Again, For 3 Km the man takes = 60 minutes
For 1 km the car takes = $\frac{60}{3}$ minutes
= 20 minutes
The man reaches the car after (20 — 2) = 18 minutes
7450 TK
The cost of 200 shares = 175 x 200 = Tk. 35000
Total dividend = 200 x 2.25 = Tk. 450
No. of bonus share = 200 + 5 = 40
The cost of bonus = 40 x 175 = Tk. 7000
His total gain = 7000 + 450 = Tk. 7450
8 days
The man binds 112 books in one day
His assistant binds in one day = 112 of $\frac{1}{4}$
= 28 books
They bind in 2 days alternatively = 112 + 28
= 140 books
So, they bind alternatively l40 books in = 2 days
They bind alternatively 560 books in = $\frac{2\cdot560}{140}$
= 8 days
12 %
Let, the trader bought x dozens of mangoes & x dozens of apples.
1 dozen mango costs = 150 Tk.
1: dozen mango costs = 150x Tk.
1 dozen apple costs = 100 Tk.
x dozen apple costs = 100x Tk.
(x + x) = 2x dozens fruits cost (150x + 100x) = 250x Tk.
Again, Selling price 1 dozen of fruits = 140 Tk.
Selling price 2:: dozen of fruits = 2x x 140 = 280x Tk.
Profit percentage = $\frac{30x\cdot100}{250x}$ = 12%.
1,00,000 voters.
Let, total number of voters = x
0.55 of 0.75x— 0.45 of 0.75x = 7500
=> 0.10 x 0.75x = 7500
=> 0.075x = 7500
=> x = $\frac{7500000}{0.075}$ = 1,00,000
TK 400
Suppose, the price of Pen Tk. x
The price of pen-stand = Tk. (1,000 —x)
At 20% profit,
If the cost Tk. 100 then selling price = Tk. 120
If the cost Tk. x then selling price = Tk. $\frac{120x}{100}$
At 15% loss,
if the cost Tk. 100 then selling price = Tk. 85
If the cost Tk. (1,000 —x) then selling price = Tk. $\frac{(100-x)85}{100}$
At overall 6% profit,-
If cost Tk. 100 run selling price = 106
If cost Tk. 1,000 run selling price = $\frac{106\cdot1000}{100}$
= Tk. 1,060
According to the question,
$\frac{120x}{100} + \frac{85(1000-x)}{100}$ = 1060
=> $\frac{120x+85000-85x}{100}$ = 1060
=> 35x+ 85000 = 106000
=> x= $\frac{106000-85000}{35}$ = 600
The cost of pen = Tk. 600 and pen-stand = 1000 — 600
= Tk. 400
10 year
Interest : Investment = 3 : 6
Sum ofthe this ratio = 3 + 6 = 9
Interest = 45,000 of $\frac{3}{9}$
= Tk. 15,000
Investment = 45,000 of $\frac{6}{9}$
= Tk. 30,000
At 5% rate of interest,
The interest of Tk. 100 is Tk. 5 for= 1 year
The interest of Tk. 1 is Tk. 5 for = 100 x 1 year
The interest of Tk. 1 is Tk. 1 for=$\frac{100}{5}$year
The interest of Tk. 30000 is Tk. 1 for = $\frac{100}{5\cdot30000}$ year
The interest of Tk. 30000 is Tk. 15000 for = $\frac{100\cdot 15000}{5\cdot30000}$ year
= 10 year
400 female
Let, in 1998 female students were x
The male students were = (900 —x)
At 4% male students left,
Among 100 male students left = 4
Among (900 -x) male students left = $\frac{(900-x).4}{100}$
= $\frac{900-x}{25}$
Again, 5% female students new,
Among 100 female students joined = 5
Among x female students joined = $\frac{5x}{100} = \frac{x}{20}$
According to the question,
$\frac{900-x}{25} = \frac{x}{20}$
=> 25x = 18000-20x
So, x = 400
36 TK
At 16.6666% reduction, the present cost = Tk. (100 — 16.6666)
= Tk. 83.3334
When present cost Tk. 83.3334 then past cost = Tk. 100
When present cost Tk. 75 then past cost = Tk. $\frac{100\cdot75}{83.3334} $
= 90 Tk.
So the current price of 5 bananas = Tk. (90 — 75) = Tk. 15
The current price of 5 bananas = Tk. 15
The current price of 1 banana = Tk. $\frac{15}{5} $
The current price of 12 bananas = Tk. $\frac{15\cdot12}{5} $
= 36 Tk.
