Question

Ratio of incomes of $A,B$ and $C$ last year was $3:4:5$. The ratio of their individual incomes of last year and this year are $4:5,2:3$ and $3:4$ respectively. If the sum of their present incomes is Rs. $78800$. Find the present individual income of $B$

• A. Rs. $18000$
• B. Rs. $32000$
• C. Rs. $28800$
• D. Cannot be determined

Answer 1

The correct option is C Rs. $28800$

Let the previous incomes of $A,B$ & $C$ be $3x,4x$ & $5x$ respectively, when $x$ is in Rs and

let the present incomes of $A,B$ & $C$ be $p,q$ & $r$ respectively.

Then, the previous income of

$A$ $:\frac{3x}{p}=\frac{4}{5}$

$\Rightarrow p=\frac{15x}{4}$,

$B:\frac{3x}{p}=\frac{4}{5}$

$\Rightarrow q=\frac{12x}{2}$,

$C:\frac{5x}{r}=\frac{3}{4}$

$\Rightarrow r=\frac{20x}{3}$

So, the sum of their present incomes

$=p+q+r=$ Rs. $78800=$ Rs. $(\frac{15x}{4}+\frac{12x}{2}+\frac{20x}{3})$

$=$ Rs. $\frac{197x}{12}$

$\Rightarrow x=\frac{12}{197}\times 78800$

$=$ Rs. $4800$

$\therefore \frac{12x}{2}=$ Rs. $6\times 78800=$ Rs. $28800$

which is B's present income.

Ans- Option C.