The cost of manufacturing a sofa is S$1500. It is sold to a retailer at a profit of 15% of the cost. Calculate the price the retailer paid for the sofa. Answer S$ ... At a furniture fair, the retailer then sold the sofa to a customer at S$2250. Calculate the retailer's profit for the sale of the sofa as a percentage of the selling price. Answer ...% John changed S$3500 into US Dollar (US$) at a bank, for his trip to the United States. Upon his return, he still had US$78 left in his wallet. The table below shows the exchange rate between Singapore dollar (S$) and US dollar (US$) at the bank upon his return. Calculate the amount he spent in Singapore dollar (S$) for his trip to the United States. Answer S$ ...

1. Increase the cost price by 15% to find the price paid by the retailer.

Profit $=15\%$ of S$1500

Price paid by retailer
$=1500+15\%\times1500$

$=1500+0.15\times1500$

$=1500+225=1725$

1. Find the retailer's profit from selling the sofa.

From part (a)(i), the retailer paid S$1725 for the sofa.

Profit $= 2250 - 1725 = 525$

2. Express the profit as a percentage of the selling price.

$\frac{525}{2250} \times 100\% = 23.333\ldots\%$

$\approx 23.3\%$

1. Find the Singapore dollar value of the US\$78 left over.

Since John is changing US dollars back to Singapore dollars, use the bank's buying rate.

$\text{Value of US\$78}=78\times 1.34=104.52$

So the amount left over is S$104.52.

2. Subtract the value of the unspent money from the original amount changed.

$\text{Amount spent}=3500-104.52=3395.48$