Silvered slab problem: why is k positive when I got it negative?

[zorro]

Homework Statement

A point object is placed at distance of 40 cm from a composite refracting slab whose one face is silvered as shown. The separation between the object and its final image is (100 – k)cm. Find the value of k.

The Attempt at a Solution

I got the separation as 102cm. So k= -2
But the answer given is +2 and I am sure of my answer. Can somebody verify it?

 

[cupid.callin]

cant see the image :p

 

[zorro]

I could see it. May be some problem. I reattached now.

 

[ehild]

[
I got the separation as 102cm. So k= -2
But the answer given is +2 and I am sure of my answer. Can somebody verify it?

I got he same.

ehild

 

[zorro]

Thanks!

 

[SammyS]

I also get 102 cm.