Interesting one!
Distance, d
Speed, V
Time, t
Let us call meeting point, X
d = Vt
1. X = 90t
2. X = 100( t - 10)
But 1=2
90t = 100( t - 10)
90t = 100t - 1000
- 10t = - 1000
t = 100
t = 100 minutes
t = 100/60
t = 1.666 hrs
meeting point, X
substituting to either 1 or 2 since they are equal, taking 1.
X = Vt
X = 90 x 1.666
= 149.94
approx X = 150 km.