Two friends, Rajib and Rahat, entered into a partnership investing Tk. 700 and Tk. 600 respectively. After 3 months, Rajib withdrew 2/7 his investment but after 3/5 months, he reinvested 3 of what he had withdrawn. The profit at the end of the year was Tk. 726. If the profit was shared according to time weighted investment, then what was the difference between the profits of those two friends?

Explanation: Rajib এর initial investment 700 টাকা যেটা 3 months খাটল। সে withdraw করল = \(700 \times \frac{2}{7} = 200\) টাকা; অর্থাৎ, পরের 3 months \((700-200)=500\) টাকা খাটল, then সে re-invest করল \(200 \times \frac{3}{5} = 120\) টাকা অর্থাৎ বাকী 6 months \((500+120)=620\) টাকা খাটল। সুতরাং Rajib এর time-weighted total = \((700 \times 3) + (500 \times 3) + (620 \times 6) = Tk. 7320\) আর, Rahat এর time-weighted total = \((600 \times 12) = Tk. 7200\) অর্থাৎ Total investment = Tk. \((7320+7200)= Tk. 14,520\) investment এর time-weighted ratio এর difference = Tk. \((7320-7200)= Tk. 120\) এখন, 14520 হলে difference = 120 726 হলে difference = \(\frac{120 \times 726}{14520} = Tk. 6\)]