1. Only Z is taught before R. (Means R taught on Tuesday because only Z is taught before R) 2. T is not taught on Wednesday. 3. T is taught before X. (So, T is taught on Thursday because T is not taught on Wednesday)
सोमवार
Z
मंगलवार
R
बुधवार
गुरुवार
T
शुक्रवार
X
4. V is taught on remaining day that is Wednesday.
सोमवार
Z
मंगलवार
R
बुधवार
V
गुरुवार
T
शुक्रवार
X
So, there are 2 subject taught before V. Thus, the correct answer is “2”.