In a kaleidoscope, a pattern seen once can never be seen again.

The image of an object persists on the retina of an eye for about _____ second even after the object has disappeared.

Choose the answer from the options given in the bracket. ($\frac{1}{16}$,$\frac{1}{6}$,$\frac{1}{9}$ )

In a movie, the still pictures in proper sequence are projected on the screen usually at the rate of _____ pictures per second.