If a U. S. citizen could buy £25,000 for $100,000, the rate of exchange for the pound would be

The rate of exchange for the £ is US$ 4

Explanation:

1. Let's check the information provided to answer the question correctly:

Amount the U. S. citizen want to buy in £ = 25,000

Amount the U. S. citizen will pay in US$ = 100,000

2. Let's calculate the rate of exchange for the British pound £, this way:

Rate of exchange = Amount in US$/Amount in £

Rate of exchange = 100,000/25,000

Rate of exchange = 4 US$ per £

We can also express the rate for the US$, this way:

Rate of exchange = Amount in £/Amount in US$

Rate of exchange = 25,000/100,000

Rate of exchange = £ 0.25 per US$