in country x, a decrease in the average currency exchange

2% dec CER yields +10 ---->1% dec CER yields +5, hence 1% inc = -5
1% inc AMR yields +10

so 10-5 = +5

yeah..its C

C it is....

If AMR increase by 1% that leads to a 10point increase....end of story...AMR increased by 1% therefor price index should increase by 10 points! if CER decrese prince index increases....by 10 points, if CER increases price point decreases....therefor 1% CER increase leades to -5 reduction in the index!

10-5=5

Christoph, I think I got it : it's D right ?

We just have 2 elements :

if there is a decrease in the average currency exchange rate - CER - of 2% -> 10-point increase in the national retail price index.
OR
if there is an increase of the average mortgage rate - AMR - of 1% -> 10-point increase in the national retail price index.

so we can not assume the effects if there is :
an increase of CER
a decrease of AMR
it would just be assumptions

Moreover the 2 conditions are linked with "OR" wich means that one condition is enough to get the result, and as we don't know the consequences of a 1% increase in CER...

just the increase of AMR is verified so it leads to answer D

"D" for me.

We know that only a decrease in CER makes the national point to go up, so I think we shud only consider the increase in AMR which wud effect, which will be +10.