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What might you do with your infinite series to roughly estimate the NPV in your head without having to write anything down? Especially when faced with certain
by jerrya 13y ago
What might you do with your infinite series to roughly estimate the NPV in your head without having to write anything down?
Especially when faced with certain tradeoffs, like comparing a $6B hyperloop with an agency with an annual budget of $10B?
- T-hawk 13y agoJust divide the yearly cost by the rate of interest or inflation. $10 billion divided by 3.71% yields that $270 billion figure. Use whatever mental shortcuts work for arithmetic in other contexts. There's no need for an actual infinite series. Explaining it the other way around, if you had $270 billion now, you could fund the NSA by $10 billion per year in perpetuity based on the interest. That's a simple calculation of $270B x 3.71%.
- jerrya 13y agoMust just be me. How about: I'll trade 7 1/2 months of the NSA annual budget for one hyperloop.