PLEASE HELP!!!!!!!!!!!!!!!! (answer in decimal!!!!!!!!)

9514 1404 393
Answer:
0.75
Step-by-step explanation:
You know that ...
P(S or T) = P(S) +P(T) -P(S and T)
When events are mutually exclusive, P(S and T) = 0. Then ...
P(S or T) = 5/8 + 1/8 = 6/8 = 3/4
P(S or T) = 0.75