jnu 2012 doubts!

[taanya]

If someone could please help me the correct way to solve questions 70-75 and 88-92 in the 2012 paper??

Also in q 70 shouldnt the principal sum be given that is deposited in the fd account???so according to me the correct answer should be option (D).please confirm...

[Akshay Jain]

sol for 88-92
it is given that the value of each cow's production is V(n)
for 1 cow it is 22 rs
for 2 cows it is 18+18=36 rs n so on
sol 88. for max profit MR=MC
at n=4 the profit max condition is satisfied (we have to take descrete units)
each cows production value is 12 and mc=11.
sol 89. we have to max the difference between TR and TC
for n=1 TR-TC= 22-11=11
for n=2 TR-TC=18+18-22=14
for n=3 TR-TC=15+15+15-33=12
chek for all values of n
so n=2
sol 90. in equilibrium 4 cows will be purchased
TR-TC=12*4-11*4=4
sol 91. cnt undrstand
sol 92. after tax total cost will be 21 per cow so only 1 cow will be purchased. tax revenue is rs 10

[taanya]

THANK U SO MUCH AKSHAY JAIN!!

[AS]

for 91 n.v(n)-n(11+t) >0
since the number of cows that maximises the village's aggregate income is 2 we have

2(18)-2(11+t)>0
so we get t<7
hence i guess t=6 should be the correct answer

[AS]

for 91 n.v(n)-n(11+t) >0
since the number of cows that maximises the village's aggregate income is 2 we have

2(18)-2(11+t)>0
so we get t<7
hence i guess t=6 should be the correct answer

[jess]

I think that the logic is this for 91(b)

You have to make sure that the total number of villagers end up buying 2 cows. Thus, MC=MR holds when 11+t is roughly equal to 18 (MR of 2 cows).

This happens at t=7. but at t=7, aggregate income of village = 36 - (11+7)x2 = 0

for t = 6, they buy 2 cows, and agg income = 2

then for t = 0, individuals end up buying 4 cows instead. t=11 means MC=22 by individual. thus only 1 cow is bought. so condition is not satisfied

for t<6. say t=5, MC= 16 and t=4, MC falls even further thereby increasing number of cows grazed.

for 6<t<11 MC>MR for n = 2 (so not applicable)

anything beyond t>11, no cow is bought.

Thus only t=6 is possible.

[taanya]

HEY THANKS!
even i reached the same conclusion....
can u help me out with this??
1) X & y are two statements.If we know x implies y then
a.X true, then Y also true
b.X false, then Y is false
c.Y true, then X is true
d.Y false, then X is false

2)X,Y,Z are statements and X implies Y,Y implies Z. also X is false, then
a.Y is true, Z is false
b.Y is false,Z is true
c.both Y and Z are false
d. None of above

[jess]

For 1st logic question, (a) is answer. My reasoning is as follows:

(c) means Y -> X and not X -> Y
(d) is the contrapositive of X -> Y
(b) if X is false, Y can be false or true and statement X->Y still holds



So (a) is the stronger option i think,

as X-> Y is false when X is true and Y is false. but if X is true, Y also has to be true always.