Given:
• R1 = 3 Ω
,
• R2 = 4 Ω
,
• R3 = 4 Ω
,
• R4 = 1 Ω
Let's find the equivalent resistance between A and B in the given circuit.
R3 and R4 are connected in parallel.
To find the equivalent resistance (R5) of R3 and R4 since they are connected in parallel, we have:
![\begin{gathered} (1)/(R_5)=(1)/(R_3)+(1)/(R_4) \\ \\ (1)/(R_5)=(1)/(4)+(1)/(1) \\ \\ (1)/(R_5)=(1+4)/(4) \\ \\ (1)/(R_5)=(5)/(4) \\ \\ R_5=(4)/(5)=0.8\text{ \Omega} \end{gathered}]()
Now, R1, R2, and R5 are will be series.
To find the equivalent resistance, we have:

Therefore, the equivalent resistance between A and B in the figure is 7.8Ω.
ANSWER:
7.8Ω