A Vietnamese guy in Houston calls a foreign exchange counter and asks how many pesos he can get for $100.

The person on the other end answers "1900".

The Vietnamese guy shows up to the foreign exchange place the next morning and hands the $100 and asks for pesos.

The guy at the counter gives him 1850 pesos.

The customer is confused. He says, "but when I called yesterday, you said 1900. Why am I only getting 1850 pesos now?"

"Fluctuation", answers the guy at the counter.

The customer responds: "Well fuck you too, white guy!"