A hot air balloon is 10 feet off the ground and is rising at a constant rate of 2 feet per second. What is the height of the balloon, in feet, after 25 more seconds?

Rising at a constant rate of 2 feet per second, it will rise 2 x 25 = 50 feet in 25 seconds.

Since it starts 10 feet off the ground, it's height is 10 + 50 = 60 feet.