Two hot air balloons, one purple and one gold, took off at the same time. The purple balloon started from sea level and the gold balloon started from a hill 15 meters above sea level.

The gold balloon began climbing at a constant rate of 2 meters per second. The purple balloon began climbing at 2.5 meters per second.

After how many seconds were the balloons at the same altitude?

1 answer

Let's denote the time in seconds as t.

For the gold balloon:
Altitude = 15 + 2t

For the purple balloon:
Altitude = 2.5t

To find when they are at the same altitude, we set their altitudes equal to each other:
15 + 2t = 2.5t
15 = 0.5t
t = 30

Therefore, the balloons were at the same altitude after 30 seconds.