View all: SOUTHEAST BANK (PO) | WRITTEN QUESTION (MATH) SOLVE | 2016
Correct Answer: ans: The cost price of book and pen is 1200 & 1400 Tk. respectively.
Explanation:
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