George is firing flashes at Gracie at the rate of 10 per second, according to his own watch. Gracie is racing away from George at a speed of $v=\frac{3}{5}c$. What is the rate at which Gracie receives the flashes?

George is firing flashes at Gracie at the rate of 10 per second, according to his own watch. Gracie is racing toward George at a speed of $v=\frac{3}{5}c$ (the same speed as in the previous question, but in the opposite direction). What is the rate at which Gracie receives the flashes?