GATE Computer Science (CS) 2015 Shift 2 Solved Paper

A half adder is implemented with XOR and AND gates. A full adder is implemented with two half adders and one OR gate. The propagation delay of an XOR gate is twice that of an AND/OR gate. The propagation delay of an AND/OR gate is 1.2 microseconds. A 4 - bit ripple - carry binary adder is implemented by using four full adders. The total propagation time of this 4 - bit binary adder in microseconds is ________.(Do not consider parallelization).