A transformer for a laptop computer converts a 120-V imput to a 24-V output

If that's all the computer's power supply/battery charger did, then you

could ask the question "What is the ratio of the number of turns in the

transformer's primary winding to the number of turns in the secondary

winding?", and we could answer it.

The ratio of turns in a transformer's primary and secondary windings

is nominally the same as the ratio of the AC voltages in each winding.

If the ratio of the voltages is (120 volts AC/24 volts AC) = 5, then the

primary winding has nominally five times as many turns as the secondary

winding has.

But ...

What the computer's power supply/battery charger actually does is

take the 120 volts AC from the wall outlet, and deliver 24 volts DC to

the laptop.

There's a lot more in that little black brick than just a simple transformer.

Finally and in conclusion, I have to ask: What's your question?