A-Level Mechanics question help

A helicopter is hovering at rest above horizontal ground at the point H. A
Parachutist steps out of the helicopter and immediately falls vertically and freely
under gravity from rest for 2.5 s. His parachute then opens and causes him to
immediately decelerate at a constant rate of 3,9 m/s^2 for T seconds (T < 6), until
his speed is reduced to V m/s, He then moves with this constant speed V m/s
until he hits the ground. While he is decelerating, he falls a distance of 73.75 m.
The total time between the instant when he leaves H and the instant
when he hits the ground is 20 seconds.
The parachutist is modelled as a particle.

Find the Speed of the parachutist at the instant when his parachute opens

Find the value of T

I can't seem to figure it out, any ideas?

Sketching the information usually helps, so upload what youve tried.

But its obviously a 3 stage suvat problem, where each stage represents a phase with constant acceleration. The speed when the parachute opens is the first phase and you should be able to do it as its a single suvat?

Apologies, should have made it a little clearer, I can find the speed completely fine, it is with finding T that I'm struggling with.

I placed the speed part in there to give a little more context

What have you sketched/written down about the info you know - can you upload what youve tried. The aim is (obviously) to combine a couple of suvats involving T and V for the 2nd and 3rd phase to get T.

Surely you can find T from the information you've been given/calculated so far (you have u, a, and s) without needing V?

Looks like it. Was only 1/2 concentrating and missed the bit about the decelerating distance, though was half hoping the op would post some form of attempt.

I understand not really wanting to get involved until the OP has shown some effort - I had some difficulty phrasing my comment so it wouldn't reward someone looking for the answer without putting in any effort!