Problem
Exchange rates Faisal lives in the USA. He wants to buy one cotton sheet. In the USA one sheet costs 79 US dollars. Faisal knows that the same type of sheet costs 210 Egyptian pounds when bought in Egypt. He also knows these exchange rates. \[ \begin{array}{|l|} \hline 1 \text { euro }=1.10 \text { US dollars } \\ 1 \text { euro }=9.72 \text { Egyptian pounds } \end{array} \] \begin{tabular}{|l|} \hline 1 euro $=1.10$ US dollars \\ 1 euro $=9.72$ Egyptian pounds \\ \hline \end{tabular} How much cheaper is the cost of one sheet when bought in Egypt than when bought in the USA? Give your answer in US dollars correct to the nearest dollar.
Solution
Step 1 ：Convert the cost of the sheet in Egypt from Egyptian pounds to euros: \(210 \text{ Egyptian pounds} \times 0.10288065843621398 \text{ euro/Egyptian pound} = 21.604938271604937 \text{ euros} \)
Step 2 ：Convert the cost of the sheet in Egypt from euros to US dollars: \(21.604938271604937 \text{ euros} \times 0.9090909090909091 \text{ US dollars/euro} = 23.765432098765434 \text{ US dollars} \)
Step 3 ：Find the difference between the cost of the sheet in the USA and Egypt: \(79 \text{ US dollars} - 23.765432098765434 \text{ US dollars} = 55.23456790123457 \text{ US dollars} \)
Step 4 ：\boxed{55} US dollars cheaper when bought in Egypt
