Question

two jets are 2370 km apart and travelling toward each other, one at 720 km/hr and the other at 860 km/hr. how far does each travel before they pass

Answer 1

The scenario is something like this, A is first jet, B is second jet, P is point of crossing,

A-->.................................(d = 2370)..................................<-----B
velocity=720 (for first jet A) '''''''''[P]'''''''''' (for second jet B) velocity=860

Now say the jets fly for t seconds, before meeting at P,
So, distance covered by A = 720 * t
And distance covered by B = 860 * t

-> 720 * t + 860 * t = 2370
-> 1580 * t = 2370

$t = \frac{2370}{1580} \\ \\ t = \frac{237}{158} \\ \\ t = \frac{(79) (3)}{(79)(2)} \\ \\ t = \frac{3}{2} \\ \\ t = 1.5$

So distance covered by A = 720 * 1.5 = 1080 km
And distance covered by B = 860 * 1.5 = 1290 km

Answer
1080 km, 1290 km

Answer 2

relative speed of one with respect to the other= 720 +860 =1580
time taken to pass each other = 2370/1580 = 1.5 hr
distance travelled by first jet = 1.5 * 720 = 1080 km
distance travelled by t h esecond jet = 1.5 * 860 = 1290 km