A parachutist bails out and freely falls 64.7 m. Then the parachute opens and thereafter she decelerates at 1.88 m/s2. She reaches the ground with a speed of 3.07 m/s. What is her average speed (in m/s) for the fall?

Question

A parachutist bails out and freely falls 64.7 m.  Then the parachute opens and thereafter she decelerates at 1.88 m/s2.  She reaches the ground with a speed of 3.07 m/s.  What is her average speed (in m/s) for the fall?

I was planning on finding the time before she decelerated using x=v0t - (1/2)at^2, where x=64.7m, a=-9.8m/s^2(because of gravity during free fall), v0 = 0m/s and solving for t1. Now to find the time she falls after she decelerates using vfinal = v0 +at, vfinal = 3.07, a=-1.88, and solving for t2. Then subtracting the two to find delta t.

And to find average speed I would use total distance = 64.7, divided by delta t It doesn't seem to give me the right answer, am I doing everything right?

And to find average speed I would use total distance = 64.7, divided by delta t It doesn't seem to give me the right answer, am I doing everything right?