How to utilize Rs. 98 rate cutter ?

First let me tell what this 98 Rupee rate cutter offers you.
1.Vodafone to vodafone local calls @ 10 paise per minute.
2.Vodafone to other mobile local calls @ 49 paise per minute.
3.STD to Vodafone numbers @ Re 1/ min and
4.STD to other mobiles @ Rs 1.50 / min

Now there might be three cases , first is you call mostly to vodafone mobiles , second is you call more to other mobiles and third is you call equally to both vodafone and other mobiles.

For the first case :
If you are going to talk only to vodafone mobiles then you have a better rate cutter than this , that is Rs. 65 rate cutter (Calls to Vodafone mobile phones in Tamil Nadu @ 10p / min).So if you fall under case 1 please forget about 98 rate cutter.

Second case :

If you call 20% to vodafone and 80% to other
Let us assume that you recharge for Rs. 199 after putting that rate cutter .
Talk time for that 199 RC(Recharge) is 46.11.
So you use 9.22 for vodafone and 36.88 for other mobiles.
So no.of calls to vodafone is 9.22/.10=92.2 calls
No. of calls to other mobiles is 36.88/.49=75.2 calls.
total no. of calls is 75+92=167........................equ(1)
This leads to a loss of only 13 calls..
because if you didn't apply the rate cutter then your talk time 46.11 + 89(instead of rate cutter if you top up for 100 talk time around 89 ) =135 .
So you can make 135/.75=180 calls..............equ (2)

Therefore from equ(1) and equ(2) 180-167 =13 calls loss .........equ (3)

Third case :

Let us assume that you recharge for Rs. 199 after putting that rate cutter .
Talk time for that 199 RC(Recharge) is 46.11.
If you use that 46.11 equally for calling to vodafone and other mobiles i.e 23.055 for vodafone and 23.055 for other mobiles.
Since for vodafone its 10 paise/min you can call for 23.o55/.10= 230.55 min i.e 230 calls.
Since for other mobiles its 49 paise/min you can call for 23.055/.49= 47.05 min i.e 47 calls.
So you totally make 230 +47 =277 calls.......................equ( 4)
This leads to a profit of 97 calls.
because if you didn't apply the rate cutter then your talk time 46.11 + 89(instead of rate cutter if you top up for 100 talk time around 89 ) =135 .
So you can make 135/.75=180 calls..............................equ (5)

Therefore from equ (1) & (2) 277-180=97 calls.........equ(6)

So by comparing equ (3) and (6) we can come to a conclusion that you get benefitted only when you fall under case 3.