Method 2
Let p= P(Bob wins)
Then p= 1/4+1/2*1/4+1/2*1/4*p+1/4*p
where 1/4=P(Bob wins first toss)
1/2*1/4=P(Bob wins on second toss after a 1 Head toss)
1/2*1/4=P(TT after a 1 Head toss)
1/4=P(TT on first toss)
Solve for p to get 3/5.
Yes Archman, I could now see Affinity's sol.
Let p= P(Bob wins)
Then p= 1/4+1/2*1/4+1/2*1/4*p+1/4*p
where 1/4=P(Bob wins first toss)
1/2*1/4=P(Bob wins on second toss after a 1 Head toss)
1/2*1/4=P(TT after a 1 Head toss)
1/4=P(TT on first toss)
Solve for p to get 3/5.
Yes Archman, I could now see Affinity's sol.