19 November 2013

Interesting unintended consequences. And a puzzle.

Part of an email I got from my good old friend Jyotsna from Singapore:

“Btw your puzzle format on FB was an inspiration to the math teachers at the boy’s school. I had asked the teachers to look at posting puzzles in a forum so that kids can help out each other and gave your puzzles discussion as an example. It is the second week of this discussion on the school forum and the class kids seem to love it!! So you are pretty influential in far away Singapore! :-)”

What started as an exercise to get rid of boredom on a flight back from DC a few years back has certainly had some unintentional – but highly welcome 🙂 – consequences. Thank you Jyotsna!

This puts pressure on me to post the next puzzle. This one is dedicated to the kids in Singapore and elsewhere. And also adults.

(Again, do not post in Comment section; send me FB msg; I will respond)

A few days back, I was cleaning my pool and talking to my another good friend Kuntal over the phone. He had posed a question – “what is the last digit of 19^19 + 99^99”. Over the phone we discussed our answers – he had taken an elegant way to solve it – I had used a short cut.

So let’s try that:

1. What is the last digit of the sum of 19 to the power of 19 added to 99 to the power of 99. (19^19 + 99^99).
And an extension..
2. What is the last digit of
9^9 + 19^19 + 29^29 + 39^39 +……+ 99^99

3. If you have an younger kid – or you are stuck yourself – try with the following simpler version – and then the above two become easier. What is the last digit of 99^99?

17 November 2013

Hill runs

16K (10 mile) run in the hills of Milton. After my last disastrous long run two weeks back, this one was much better. I had to slow down to almost 10:30 min/mile pace to make sure I could complete the run. The hills made sure that I did not become too adventurous 🙂

Category: Running | LEAVE A COMMENT
14 November 2013

Puzzle – populous cities

Today, my friend Gasan showed me this. I was totally stunned. The question is “What are the top cities by population in the world?”. Not the population of the metro area but just the city proper. (The metro area list is very different) . You have to do this without Googling. I will give you the city names. Can you rank them?
Try it and then check in Google. Or I will post the answers:

Beijing, Delhi, Guangzhou, Istanbul, Karachi, Moscow, Mumbai, Sao Paulo, Shanghai, Tianjin (in China)

Note that the top 4 cities by metro area population – Tokyo, Seoul, Mexico City and New York City do not figure in the above list!!!

13 November 2013

To myself and all my runner friends…

Here is a humorous take on us: http://m.us.wsj.com/articles/SB10001424052702304448204579186401818882202?mg=reno64-wsj

The text is here in case the link is not working:

November 12, 2013 6:35 PM
OK, You’re a Runner. Get Over It
Running a marathon is hard enough without also patting yourself on the back every step of the way.

By CHAD STAFKO
There is one kind of bumper sticker I see almost daily here in my small Midwestern town: a small oval printed with “26.2” or “13.1.” In case you’re lucky enough not to know what these numbers represent, let me explain: They indicate that the driver or someone in the car has run a marathon (26.2 miles) or a half-marathon (13.1 miles).
There is only one reason running aficionados display the stickers. They want the rest of us to know about their long-distance feats. So let me be the first to offer my hearty congratulations. I’d even offer to give them a pat on the back—once they’re done doing it themselves.
What’s with this infatuation with running and the near-mandatory ritual of preening about it?
Almost every day I see people running: in the city, through subdivisions or out on country roads. They’re everywhere and at all times, from dawn until dark, their reflective gear flickering along the road.
I thought I was imagining this spike in running’s popularity, but that’s not the case. According to the group Running USA, there were some 15.5 million people who finished running events in 2012, compared with approximately 13 million in 2010. These 15.5 million are hoofing it through marathons, half-marathons, 10Ks, 5Ks, fun runs, night runs, charity runs and what can only be labeled as insane ultramarathon runs of 50 miles or more.
When they’re not out there sweating through the miles, they can relax with a running magazine. There is Runners World, with its 660,000 subscribers, but also Running Times, Trail Runner, Runner’s Gazette and several others. Reading. About running.
Or these runners, when they’re not running, can go shopping—at a running store. There’s one such store less than 15 miles, or better said, just a bit over a half-marathon, from my house. It sells only running equipment and apparel. The store has been in business several years, so apparently it is making money.
This “equipment,” of course, is nothing but shoes and clothes. You can buy these same shoes at a sporting-goods store or online, probably for much less.
But the clothes—well, that’s a different story. Many of the shirts on the racks have running logos, motivational slogans and images of stick people running.
Like the 26.2 and 13.1 bumper stickers, this apparel serves a clear purpose: We can look at them and immediately know that the person wearing it is a runner—perhaps even an accomplished one.
I have several friends who are runners, or at least I did before writing this. Some have completed marathons in Nashville and Washington, D.C. One even ran the Boston Marathon.
A few days ago, one of these running friends said, after describing a recent run: “Why do I keep doing this?” I have no idea.
Why would someone want to get up at 5 a.m. and run 10 miles adorned with fluorescent tape to avoid being struck by someone who has the good sense to use a car for a 10-mile journey?
I have a theory. There is no more visible form of strenuous exercise than running. When runners are dashing down a street in the middle of town or through a subdivision, they know that every driver, every pedestrian, every leaf-raker and every person idly staring out a window can see them.
These days, people want more than ever to be seen. This is the age of taking a photo selfie and posting it on Facebook with the announcement that you’re bored—in the hope that someone will “like” that information. People want attention and crave appreciation. If you’re actually doing something like running—covering ground, staying healthy, almost even having fun—what better way to fulfill the look-at-me desire? The lone runner is a one-person parade. Yay.
OK, I know, this isn’t the case for all runners. Many of my friends who regularly run have done so for years, decades before there was a thing called social media to put humanity’s self-absorption in overdrive. These folks also tend to be infatuated with fitness anyway. If they’re not out on the streets showing the sedentary world how it’s done, they’re at the gym or in a spinning class.
But what about the others? You can spot them, wandering through the mall or killing time at Starbucks, proudly wearing their “[Fill in the blank] 5K Run” T-shirts. They’re getting what they want, without losing a drop of sweat.
I saw a great new bumper sticker the other day. It read 0.0. I’ll take one of those, please.
Mr. Stafko is a writer living in Freeburg, Ill

13 November 2013

Brrr… Below freezing!

First subzero run of the season. It was 27 degrees (-3 degrees centigrade) here by Lake Oconee. Not sure what Shelby’s biology book has to say about it but I cannot feel half my organs 🙂
On my way back, the eastern sky had started brightening up. This shot was taken of a small creek by the lake with my iPhone and terribly shivering fingers 🙂

20131113-071530.jpg

12 November 2013

What’s up, doc?

As I pulled out of my dirt road this morning, I noticed Natasha’s close friend Shelby waiting at the street corner waiting for her school bus. She was by herself and obviously very cold. So, before thinking any further, I rolled down my window and asked her if she would like a ride to her school. To which, she readily agreed. It appeared that Natasha and Sharmila missed her by a few minutes.
The drive to school – which was a slight detour for me, but I had a two hour drive to Lake Oconee in front of me – was very insightful. I am really impressed with how mature kids are these days and their clarity around what they want to do. After asking about her parents, I inevitably came to the “What do you want to be when you grow up” question.
I am not sure, why I always ask that question – maybe because my dad used to ask me and my friends the same question. Or maybe I am simply looking for some ideas for myself 🙂
Anyways, Shelby was clear she wanted to be a doctor. I immediately made a note of how my dad would have been proud of that answer. In his world, everybody grew up to be an engineer or a doctor. Or a Nobel Prize winner!!!
“Tell me a little more”, I prodded Shelby. She went on to explain how she is fascinated by what she has been studying in Biology regarding how organs work. She thinks it is an incredible feat of our body how all the organs work in tandem. She also realizes that for many people those organs do not work perfectly. So, she wants to “fix” the organs for those people.
It was a good chat for 10-15 minutes. After I dropped her and hit the road for the long haul, my mind kept going back to my tenth grade (Shelby is a tenth grader). I had a Biology book too. (It was a red book by two authors – Katyal and Ali, as I reckon). And my Biology book had chapters on organs too. But to me, every new organ was an obstacle to getting myself a passing grade 🙂
And yet, from these same chapters, this girl has started building her dream.
I am truly impressed with how kids learn so much more, faster and exhibit greater level of maturity and independence in deciding who they want to be.
Don’t you let anybody tell you that this world is not getting better and brighter…