For the given logic circuit, which of the following inputs combination will make both LED -1 and LED -2 to glow?

Step-by-step solution

Let the output of the OR gate be Y₁ . Y₁ = A + B For LED-1 to glow, Y₁ must be 1 , which means A + B = 1 . Let the output of the first AND gate be Y₂ . Y₂ = Y₁ C = (A + B) C Let the output of the second AND gate be Y₃ . Y₃ = A Y₂ = A (A + B) C For LED-2 to glow, Y₃ must be 1 . Simplifying the Boolean expression for Y₃ : Y₃ = (A A + A B) C Y₃ = (A + AB) C Y₃ = A(1 + B) C Y₃ = A C For Y₃ = 1 , we require A = 1 and C = 1 . If A = 1 , then Y₁ = 1 + B = 1 for any value of B , satisfying the condition for LED-1 to glow.