M1 help (again) - sorry

Sorry guys, I'm stuck again.

Two cyclists A and B are travelling in the same direction along a straight road. B is travelling at a speed of 9ms^-1 and A is overtaking B at a speed of 10ms^-1. At the moment when they are level they see a traffic light turn red 108m ahead. A cycles for T seconds and then decelerates uniformly; B cycles for 6s and then decelerates uniformly. A and B stop at the traffic light at the same instant.

Calculate the time during which B was decelerating.
Calculate the value of T.

I really don't get this.

Sorry guys, I'm stuck again.

Two cyclists A and B are travelling in the same direction along a straight road. B is travelling at a speed of 9ms^-1 and A is overtaking B at a speed of 10ms^-1. At the moment when they are level they see a traffic light turn red 108m ahead. A cycles for T seconds and then decelerates uniformly; B cycles for 6s and then decelerates uniformly. A and B stop at the traffic light at the same instant.

Calculate the time during which B was decelerating.
Calculate the value of T.

I really don't get this.

B: in 6s travels 9*6 = 54m
therefore 54m left

v^2 = u^2 + 2as
0= 81 +2a(54)
108a = -81
a= -0.75

v=u+at
0=9-0.75t
t=12s


A: s =10T + ut +0.5at^2
t= 12+6 (from part one)
108 = 10T +10(18-T)+0.5a(18-T)^2

v=u+at
0=10+a(18-T)
a=-10/(18-T)

108 = 10T+10(18-T) +0.5(-10/(18-T))(18-T)^2
108 = 10T+180-10T -5(18-T)
5T = 108-180+90 = 18
T = 3.6s

I've probably made a mistake somewhere. Do you know what the answers are?