ans: The cost price of book and pen is 1200 & 1400 Tk. respectively.
Let, cost price of book is Tk x
& Cost price of pen is Tk. y
At, 25% profit the selling price of book will be = (x + x $\times$25%) Tk.
= $x+\frac{25x}{100}=\frac{5x}{4}$ TK
At, 10% profit on pen, the cost price of pen will be = (y + y x 10%) Tk.
= (Y+$\frac{10y}{100}$) = $\frac{11y}{10}$ TK
According to question, $\frac{5x}{4}$ + $\frac{11y}{10}$
=> 25x + 22y = 60,800 …………………………….(i)
In the same way we can form another equation as below
$\frac{11x}{10}$ + $\frac{5y}{4}$ = 3,070
=> $\frac{22x+25y}{20}$ = 3,070
=> 22x+25y = 61,400………………………….(ii)
Subtracting equation (i) from (ii) we will get
550x + 625y = 1535000 [Multiplying by 25]
550x + 484y = 1337600 |Multiplying by 22|
141y = 197400
y = 1400
Putting y = 1400, in equation (i) we get
25x + 22 x 1400 = 60800
=> 25x = 60800 – 30800
=> 25x = 30000
x = 1200
income separately in terms of interest & wages will be Tk. 100 & Tk. 400 respectively.
Let, (i) stands for interest
& ‘W’ stands for wage.
According to question, I + W = 500 (i)
Afier 50% increas in wage, wage will be = (w + 50% of w)
= ( W+$\frac{50w}{100}$) = $\frac{3w}{2}$
So, according to question, we get, 21+$\frac{3w}{2}$ = 800 ……………………(ii)
Now, from equation (ii), we get
21+ $\frac{3w}{2}$ = 800
=> 2(500-w)+$\frac{3w}{2}$ = 800
=> 1000-2w+ $\frac{3w}{2}$ = 800
=> 2w – $\frac{3w}{2}$ = 200
=> 4w – 3w = 400
w = 400
Now, putting w = 400 in equation (i) we get
I+ 400 = 500
I = 100
Income separately in terms of interest & wages will be Tk. 100 & Tk. 400 respectively.
