When an airplane leaves the runway, its angle of climb is 20° and its speed is 335 feet per second. How long will it take the plane to climb to an altitude of 10,000 feet? 16,000 feet?

Here is how I am thinking about it:

335 * 60 = 20100

then 10,000 / 335 = 29.85 seconds.

I am not sure if this is right but it is a guess. Could some one help me.