Question

Two jets leave Tulsa at 3:00 p.m. traveling in opposite directions. The northbound jet is flying at a rate of 850 km/h and the southbound jet is flying at a rate of 750 km/h. At what time will they be 4,000 km apart?

Answer 1

Let X = the number of hours

Plane 1 equals: 850x
Plane 2 equals: 750x

850x + 750x = 4000

1600x = 4000
x = 4000 / 1600
x = 2.5 hours

3 pm + 2.5 hours = 5:30 pm