public transportation, passes, and fares

[juldea]

So it occurs to me that since the route I take to work involves only the CT1 and the CT2 busses, and they accept both subway and bus passes, it might be cheaper for me to buy a monthly bus pass and pay cash for extraneous subway rides (as opposed to my normal method of buying a subway pass and paying for extraneous bus rides). Let's find out.

Subway pass: $44
I'd say that I fork over $2 (bus roundtrip) 1-2 times a week for odd trips. So we'll assume 6 times per month: $12
Total: $56

Bus pass: $31
I take the subway at least once a week on weekends, and randomly mid-week... so we'll assume the same 6 times/mo, only this time the roundtrips are $2.50: $15
Total: $46

So, yes. The bus pass would be cheaper by $10 a month at my current estimations.

If I settle at 6 bus trips per month, how many times do I have to ride the subway for it to not save me money?
56 > 31 + 2.5x
25 > 2.5x
10 > x

Hmm. We'll have to see if I end up riding the subway more than twice a week, then. And how much I do end up riding non-CT busses, since I have access to them.

It's delight in activities like this that make me wonder if I should really go for a graduate degree in statistics.