A student takes two tests. P(T1)=0.8P(T_1) = 0.8P(T1)=0.8, P(T2∣T1)=0.7P(T_2|T_1) = 0.7P(T2∣T1)=0.7, P(T2∣T1c)=0.4P(T_2|T_1^c) = 0.4P(T2∣T1c)=0.4. What is P(T2)P(T_2)P(T2)?
0.640.640.64
0.560.560.56
0.680.680.68