51.36 is the answer.
The equation is total=original(1+% in decimal form)
Use the identity P(A ∪ B) = P(A)+P(B)-P(A ∩ B)
P(A)=0.50
P(B)=0.60
P(A ∪ B) = 0.30
=>
P(A ∪ B) = P(A)+P(B)-P(A ∩ B)
=(0.50+0.60)-0.30
=0.80
The equation would be 0.05x + 3.15 = 5.10
0.05x = 1.95 (subtraction)
x = 39 (division)
39 minutes
