Can we see your attempt first ??

Tip - don't forget to connect the GND together

 

Can we see your attempt first ??

Tip - don't forget to connect the GND together

I tried to solve it, but then I realized that Vout shouldn't be 100. I get confused.
also I didn't know how to connect GND together

 

Try again but this time with this redrawn circuit by me:

 

Try again but this time with this redrawn circuit by me:
View attachment 94337

It worked ! thank you

 

It wasn't that hard after all ?

 

yeah
well, can I redraw this circuit in that way?

 

Yes you can, but this circuit is tricky.

 

I found that the sum of the branched currents is bigger than the primary current..why? how to solve it?

 

Because in this case only one of the two diodes can conduct, and your job is to find out which one it is (based on circuit analysis).

 

Because in this case only one of the two diodes can conduct, and your job is to find out which one it is (based on circuit analysis).

I think the solitary one is off, and the other is on
you helped me, thank you

 

Do you have any proof for that ??

 

The positive terminal of the first battery is connected to the anode while the positive terminal of the second battery is connected to the cathode and because the batteries are equivalent, they canceled out each other. Is it right?

 

No, wrong
http://forum.allaboutcircuits.com/threads/determine-diode-bias.36583/#post-229979
So what is the right answer ?