Question 846732
Tn = t * r^(n - 1)

T2 = t * r
T2+T1=135
t*r+t=135

T3 = t * r^2
T4 = t * r^3
T3+T4=60
t*r^2+t*r^3=60,
(r^3+r^2)t = 60
t*r+t=135
(r+1)*t = 135

(r^3+r^2)t = 60
(r+1)*t = 135
r = 2/3,   t1 = 81