24 year
Let, the principal amount is Tk. 100
Principal amount with interest = 100 x 4
= Tk. 400
Interest = 400 — 100 = Tk. 300
At 12$\frac{1}{2}$% or $\frac{25}{2}$ % interest
Tk. $\frac{25}{2}$ comes for = 1 year
Tk. 300 comes for = $\frac{2\cdot 300}{25}$ year
= 24 year.
1 %
increased salary at 10%
When original salary Tk. 100, then increased salary = Tk. 110
At 10% decreased salary in next month.
Changed salary 110 of 10% = Tk. 99
Percentage decreased of original salary = Tk. (100 — 99)
= Tk. 1 or 1 %
TK 200
Let, the cost price he = 100 Tk.
At 20% loss, selling price will be = (100 — 20) = 80 Tie
And at a 10% profit, the selling price would be = (100 + 10) = 110 Tk.
Difference between selling price = (110 — 80) = 30 Tk.
If he sold at 30 Tk. more then cost price = 100 Tk.
If he sold at 60 Tk. more then cost price = Tk. $\frac{100 \cdot 60}{30}$
= Tk. 200
TK 30,000
Let, the profit of Q, R, S = 2x, 5x, 8x
Respectively Total profit = 2x + 5x + 8x = 15x
According to the question,
2x = 4,000
So, x = 2,000
The profit of Q = Tk. 4,000
The profit of R = Tk. (5 x 2,000) = Tk. 10,000
The profit of S = Tk. (8 x 2,000) = Tk. 16,000
The total profit = 4,000 + 10,000 + 16,000 = Tk. 30,000
The distance between A and B is 45 miles.
Let, the distance between A and B in x km
A person travels 9 miles for = 1 hour
A person travels x miles for = $\frac{x}{9}$ hour
He returns from B to A at 15 miles for = 1 hour
He returns from B to A at x miles for =$\frac{x}{15}$ hour
According to the question,
$\frac{x}{9}$ +$\frac{x}{15}$ =8
=> 8x = 360
So, x = 45
