Can you really tell with absolute certainty whether it’s am or pm all the time? Notwithstanding your internal biological timepiece with its mysterious circadian rhythm of chronobiology or your yogic mastery of the pineal body, you can’t. Approximately maybe but not 100% ever.
However, for the purposes of this puzzle let’s assume you can. Now you’re given a clock with an hour and minute hand but not a second hand. (Meaning it’s a new clock.) Also, to your utter chagrin, those two hands are completely identical in all aspects including size, shape, colour, smell, nationality, religion, gender, caste, etc. Question: how many times per 24-hour day would you find it impossible to tell what o’clock it is?
(An extremely hoary one of yore went something like this: “When the very frazzled waitress asked people at table #17 ‘How many had coffee?’ nine put their hands up. ‘How many had milkshakes?’ Nine put their hands up. ‘And how many had both?’ Eight put their hands up. Now if seven had neither, how many were there at table #17?)
Eight people have declared they had both coffee and milkshake. Therefore these eight are common in those who raised their hands in having consumed both. Since nine have declared they have had only coffee and another nine, only milkshake, we have two people of which one had coffee only and the other, milkshake only. Now, eight plus two we have ten who have consumed either one of them or both. Add to this seven, who had nothing; we have seventeen who were at the table with the same number. -- Sanath Kumar TS, email@example.com
A small Venn diagram comprising two intersecting circles inside a rectangle easily solves the problem. Eight people who had taken both coffee and milkshake will appear inside the intersection. Coffee-takers 9 minus this 8 (= 1) will appear in the remaining part of one circle and milkshake-takers 9 minus 8 (again 1) will appear in the other circle. Neither (=7) will appear outside the circles in the rectangle. The sum of all these numbers (17) is the answer, which is available as a hint in the table number itself. -- Sheikh Sintha Mathar, firstname.lastname@example.org
She needs to only count the hands raised and bill for 9 coffees and 9 milkshakes. If she had to get the total number of persons, all she needs to do is a head count and not bother with all the math! – Dr Ramakrishna Easwaran, email@example.com
(Among the first five who also G I R are: Raghavendra Rao Hebbani, firstname.lastname@example.org; Rekha G, email@example.com; V S Baskar, firstname.lastname@example.org; Dhruv Narayan, email@example.com; r6k7b, firstname.lastname@example.org)
(The second problem was: “Can you is supply the first two limerick lines that are not really un-written here: Reversed gets time/ Whose poet a I’m/ Cursed I’m that explain me let First.”)
The whole limerick is: First, let me explain that I’m cursed./ I’m a poet whose time gets reversed./ Reversed gets time, Whose poet a I’m, Cursed I’m that explain me let first. If you read in the reverse order, it is still the same. -- Saishankar Swaminathan, email@example.com
Solutions can also be explained as follows: (1) The two lines aren’t unwritten,/ They are very much within./ Reverse the three in the last/ To get the answer fast/ And have a large grin. (2) For first two, reverse the last three./ Whatever comes out, let it be./ In this kciremil limerick/ Reversal does the trick./ Solution comes out you can see. -- Abhay Prakash, firstname.lastname@example.org
(And, finally, a word from a short-suffering saddened soul.)
Even though I sent the correct answer to the Clocking the Watch problem, you ignored it. At least you could have mentioned it under “these people also sent it”. With sadness, I remain. -- Dr P Gnanaseharan, email@example.com (Hey PG, with even more heartbreak I have to remind you that unlike the e = mc2 guy I have to play dice sometimes with the umpteen universal right answers. – MS)
BUT GOOGLE THIS NOW
There’s this small boat floating in a medium-sized swimming pool with a big fat block of ice in it. In the boat, that is. If the ice is thrown overboard and it melts, what happens to the water level? Up, down, or the same?
Sharma is a scriptwriter and former editor of Science Today magazine.