The answer is 0.5 hours.
A velocity (v) of an object is a distance (d) divided by time (t):
v = d ÷ t ⇒ t = d ÷ v
It is given:
v1 = 192 km/h
v2 = 960 km/h
t1 - t2 = 2h
We need to calculate t2.
Since they will travel the same distance before the jet overtakes the plane, we can say that d1 = d2 = d
Now, let's express t1 and t2:
t1 = d/192
t2 = d/960
Therefore: d/192 - d/960 = 2
The least common denominator is 960, so:
5d/960 - d/960 = 2
4d/960 = 2
4d = 2 · 960
4d = 1920
d = 1920 ÷ 4 = 480 km
Now t2 = d/960 = 480/960 = 0.5 hours.