7 February
2021
7 February
2021
Pushed back old age a little
6 February
2021
I am getting old
30 January
2021
From the bartender’s corner – Guava cocktail
This one is improvised from a recipe I found in a rather humorously named website.
Take two slices of lime in a muddling glass and throw in a spoonful of sugar in it. Muddle it very well. Add ice to it. Pour two ounces of rum and four ounces of guava juice in it and then shake it well.
Pour it in a glass of your choice (I used a margarita glass) and serve.
Great tropical drink. Probably more suited to summer days but I enjoyed it anyways.
30 January
2021
Puzzle: Want to feel better after a Covid test?
This math puzzle about Covid will make your jaw drop (also make you feel better after getting a test)
First, please take all precautions again Covid. If you think you got exposed or have symptoms, get yourselves tested, quarantined and everything else CDC is asking us to do. Once you have done so, think about this puzzle…
The following puzzle – which is a very real one in Covid days – is an adaptation from a puzzle I had posted last year.
The end question I am going to ask you is this:
Q1. Your Covid test came positive. What is the probability that you really have the infection?
Q2. Your Covid test came negative. What is the probability that you really do not have the infection?
As Narayan had pointed out last year, most doctors do not get this. The fact that all tests have false positives and false negatives (they are not perfect) makes the real probability unintuitively high or low.
The real answers will knock your socks off.
Ok, let’s start this:
——
1. The COVID PCR test has a false positive of about 0.5% (*See Source). Which would mean in about 200 people without the virus, the test will make a mistake in one case and say he/she has the virus.
2. The test has a false negative of 10% (** See Source) This means of 10 people who actually have the virus, the test will miss out 1 of them.
3. Assume 2% of Americans at any point of time has the virus (*** See Source)
You went to get a PCR test done. Test showed positive. What is the real probability you have the virus? Hint: It is NOT 99.5%
Take the other case – the test showed negative. What is the real probability you do not have the virus? Hint: It is NOT 90%
Both the answers will make you feel much better.
That should be good enough reason why we should LOVE math! And at the risk of Tammi – the math teacher in my friend circle – slapping my wrist, I would say, you will love the chapter on Conditional Probability.
——
Sources:
* (in reality 0.2%-0.9% per https://www.icd10monitor.com/false-positives-in-pcr-tests…)
** the actual number can widely vary – as high as 67% – depending on when you got tested after exposure. The more time you give after exposure, the more the virus gets to establish itself and lesser the false negative number. https://www.acc.org/…/variation-in-false-negative-rate…
*** I took CDC’s 25% estimated US population had it https://www.cdc.gov/…/2019-ncov/cases-updates/burden.html over 11 months and took the average as 2%. (It will be slightly higher due to ramp ups)
29 January
2021
Quarantining with Phoenix
29 January
2021
Like the good old times…
Sat down to write a letter to an old teacher of mine who helped me with Bengali in 1984 (I was not good at it). Made a valiant attempt to write the whole letter in Bengali. Landed up using a couple of English words…But writing with a fountain pen to a Bengali teacher in Bengali – that is as 1984 as it gets for me!!
29 January
2021
That bit about “Early to bed…”
Nikita had asked me to wake her up at 7 am. Which is never an issue for me. It is a different matter that after about half a dozen nudging, she eventually gets up at 8:19AM. One full minute ahead of class starting at 8:20.
This morning though, I slept in and did not even get up till 7:15. I had barely put my glasses on and picked my phone up when I was accosted by these hilarious texts from Nikita. Apparently, she has been awake since 5 and realized I did not wake up at 6 (as I told her I do – which is normally what I do.)
But you can see her funny texts here accusing me of putting up a charade. She even went to the extent of opening up a website – http://exposingrajib.weebly.com to expose by double standards!!
BTW, I was checking the website – apparently, there are more exchanges on the website – I assume from Nikita’s friends?
27 January
2021
From the bartender’s corner – Racquet Club
The three ingredients of a Racquet Club are Gin, Dry Vermouth and Orange Bitters. Interestingly enough, you can make a Leaning Tower, Delmonico or an Astorio Bianco using those exact ingredients and nothing else. It is all in the proportions.
This one has 3 ounces of gin, 1 ounce of dry vermouth and 4 dashes of orange bitters.
24 January
2021
