P invests Rs.3500 in a business. After 5 months, Q joins him with some investment. If the profit that Q gets is 50% more than that of P, then find the investment of Q.

$$ Investment \times time period =profit $$

If time period is not specified in the question assume it as 12 months

Here in this question P invests Rs 3500 in 12 months (the time period of the investment not specified)

Q invest 'x' amount in 5 months

therefore,

                             P                                                  Q

Investment         3500                                                 x

time period           12                                                  7   (Q invest after 5 months so 12-5=7 )

profit ratio       $$ 3500 \times 12 $$       :                $$ x \times 7 $$

      or                6000                              :                 x

profit that Q gets is 50% more  than p 

that is,   $$ x=150 \div 100 \times 6000 $$

              x=9000