Why is it useful to have both digital and analog input devices available when solving a problem?

It is useful to have both analog and digital devices while solving a problem.

Explanation:

It is due to the fact that, both devices have their unique properties.In Analog devices, input and output are analog signals which helps us to manipulate the signal in its original form alone. But in Digital devices we can convert the analog input signal to the digital signals. Here we can manipulate and rectify the error signal in it and we can convert it back to its original form using a digital to analog converter. Hence signals are not lost.