Which expression can be used to convert \(100\) USD to Japanese Yen (JPY) if the exchange rate is \(1\) USD = \(X\) JPY?

• A. 100 \(\times\) X
• B. X \(\div\) 100
• C. 100 \(\div\) X
• D. 100 + X

Answer: (A)

Verified step by step guidance

1. Understand the concept of currency conversion: To convert an amount from one currency to another, you multiply the amount in the original currency by the exchange rate of the target currency. This is because the exchange rate represents how much of the target currency is equivalent to one unit of the original currency.
2. Identify the given values: In this problem, the amount in USD is 100, and the exchange rate is given as 1 USD = X JPY.
3. Set up the correct mathematical expression: Since 1 USD equals X JPY, to find the equivalent amount in JPY for 100 USD, you multiply the amount in USD (100) by the exchange rate (X).
4. Compare the options provided: The correct expression for converting 100 USD to JPY is 100 × X, as this follows the standard formula for currency conversion.
5. Eliminate incorrect options: The other options (X ÷ 100, 100 ÷ X, and 100 + X) do not align with the logic of currency conversion. For example, dividing or adding the exchange rate to the amount in USD does not yield the correct conversion.