U.S. President Barack Obama (L) reacts to hitting a winner down the line against a tough volley from tennis player Caroline Wozniacki (R), one of the activities at the annual Easter Egg Roll at the White House in Washington

U.S. President Barack Obama (L) reacts to hitting a winner down the line against a tough volley from tennis player Caroline Wozniacki (R), one of the activities at the annual Easter Egg Roll at the White House in Washington

U.S. President Barack Obama plays tennis with tennis player Caroline Wozniacki, one of the activities at the annual Easter Egg Roll at the White House in Washington

U.S. President Barack Obama plays tennis with tennis player Caroline Wozniacki, one of the activities at the annual Easter Egg Roll at the White House in Washington