The price of one kilogram (kg) sugar is \(175\%\) of the price of one kg salt. If 7 kgs of sugar and 5 kgs [of salt are purchased for a total of BDT 690, what is the difference in price between 2 kgs of salt and 1 kg of sugar?]
Explanation: Let, the price of 1 kg salt is x. The price of 1 kg sugar is \(175/100x\) or, \(7/4x\). \(5x + 7\times7/4x = 690 \Rightarrow 5x + 49x/4 = 690 \Rightarrow 20x + 49x = 690\times4 \Rightarrow 69x = 2760 \Rightarrow x=40\). The price of 1 kg sugar is \(7/4\times40 = 70\). The difference is \((40\times2) - 70 = 80 - 70 = 10\).
