Question 827980
90 minutes is 1.5 hours.

Let d = distance between them at the specified time period.

Trains going opposite in direction so their distances between is the sum that each goes in that 1.5 hour time.


{{{36*(1.5)+10*(1.5)=d}}}, using rate*time=distance
{{{(1.5)(36+10)}}}
{{{1.5*46}}}
{{{highlight(d=69)}}} km