Alligation Or Mixture Ques 5

Question

$A$ and $B$ started a small business. $B$ invested Rs. 600 more than $A$. At the end of nine months from the start of the business, $B$ doubles his investment. If at the end of the year, the total profit earned was Rs. 13,800 and $A’s$ share in the profit was Rs. 4,800 what was $A’s$ investment?

(1) Rs. 1,500

(2) Rs. 1,800

(3) Rs. 1,200

(4) Rs. 900

(5) Rs. 1,000

(Bank of Maharashtra PO Exam, 26.10.2016)

Show Answer

Answer: (3)

Solution: (3)

$A’s$ investment = Rs. $x$ (let)

$\therefore$ $B’s$ investment $=$ Rs. $(x+600)$

Ratio of the equivalent capitals of $A$ and $B$ for 1 month

$=x \times 12:(x+600) \times 9+(2x + 1200) \times 3$

$=12 x: 9 x+5400+6 x+3600$

$=12 x: 15 x+9000$

$=4 x: 5 x+3000$

Sum of the terms of ratio $=4 x+5 x+3000=9 x+3000$

$\therefore$ $A’s$ share $=\left(\frac{4 x}{9 x+3000}\right) \times 13800$

$\Rightarrow\left(\frac{4 x}{9 x+3000}\right) \times 13800$ $=4800$

$\Rightarrow \frac{4 x}{9 x+3000}=\frac{4800}{13800}=\frac{8}{23}$

$\Rightarrow 72 x+24000=92 x$

$\Rightarrow 92 x-72 x=24000$

$\Rightarrow 20 x=24000$

$\Rightarrow x=\frac{24000}{20}=$ Rs. 1200