WBJECA 2025 — Computer PYQ

To construct a large multiplexer using smaller ones, we use a general formula. If you want to build an $N$-input multiplexer using 2-input multiplexers, the number of 2-input multiplexers required is $N-1$.

In this problem, we are constructing a $2^{10}$-input multiplexer.

Let $N=2^{10}$.

$$N=2^{10}=1024$$

The number of 2-input multiplexers required is:

$$\text{Required MUX}=N-1$$

$$\text{Required MUX}=1024-1=1023$$