• # question_answer A and B started a business with initial investment in the ratio 5 : 7. If after one year their profits were in the ratio 1 : 2 and the period for A's investment was 7 months, B invested the money for A)  6 months        B)  $2\frac{1}{2}$ months C)         10 months        D)         4 months

Let investments of A and B respectively be 5x and 7x and period of B's investment be y months. Then.        $\frac{(5x)\times 7}{(7x)\times y}=\frac{1}{2}\,$           $\Rightarrow$ $y=10$