Hello papa!! I need some more pocket money...!

During my engineering

First year of engineering:

In my first year, college fee was 35,000/- and pocket money given my father was 8000/- per month.(E1)

Second year of engineering:

Every year there is an increase of 10,000/- in college fee. So second year fee was 45,000/-. As there is an increase in college fee, my pocket money was reduced to Rs.6000-6500/-. Because my father’s income was constant.(E2)

Third year of engineering:

As I already mentioned, fee increases every year so in 3^rd year college fee was 55,000/-, but my pocket money was still 6500/- (same as compared to 2^nd year). Because my father’s income increased.(E3)

Fourth year of engineering:

Fee was increased to 65,000/- and even my pocket money was increased to 8500/- because my father’s income was increased again.(E4)

Here, clearly we can see how the income effects the substitution of college fee with pocket money.

If college fee is increased, then pocket money will be reduced and visa-versa, but if we don't want to compromise on consumption then the income factor (father's income) effects here.

P1-pocket money in 1st year          F1-fee in 1st year         I1,2,3-indifference curves

P2-pocket money in 2nd year        F2-fee in 2nd year            BC-budget curve          

 P3-pocket money in 3rd year           F3-fee in 3rd year                                                  

P4-pocket money in 4th year           F4-fee in 4th year