Marathon Birthday Puzzle

This week my friend Irina complained to me that her son's 17th birthday fell on the Boston Marathon Day and friends weren't able to come and celebrate with them in their Brookline home until the roads opened. Previous such coincidence was 17 years ago when her son Daniel was just born in the Beth Israel Hospital that is right along the marathon route and all the visitors got delayed till the end of the marathon festivities. Irina mused that I could probably calculate when the next such coincidence would happen and I thought why not turn it into a puzzle.

Daniel's birthday is April 21.
Boston Marathon is held on Patriots Day that is 3rd Monday in April.
Is Irina correct that the Boston Marathon coincided with Daniel's birthday only twice: in 1997 when he was born, and now in 2014? When is the next time such a coincidence will happen?

Image from Flickr, distributed under CCL.

Your thoughts and suggestions are accepted any time until midnight Eastern Time on Sunday, on our Family Puzzle Marathon. 

A New Year Riddle

Four friends - John, Jesse, Gerald and George - went to a New Year Ball with their wives. At first, each danced with his own wife only, but after midnight the couples went wild. Eileen danced with John, Arleen with Darleen's husband, Marleen with Arleen's husband, Jesse with Gerald's wife, and Gerald with John's wife.

Can you untangle - who is married to whom?

Your answers accepted any time until midnight on Sunday on our Family Puzzle Marathon. They will be hidden till then and everyone who submitted something reasonable will get a puzzle point.

This riddle is from a Russian puzzle book by C. Koval.
Party image from flickr, distributed under CCL.

Can Old Calendar Come Handy?

You have been cleaning your parents' apartment and found there a collection of old calendars for the last 10 years (2002-2011). All clean, with no scribble on them and all packed with retro images. You wish you could keep them around but you are afraid your parents may confuse the dates on the wrong calendar, unless ... you can use one of the old calendars in 2013. Can you?

Submit your answer any time until midnight Eastern Time on Sunday, on our Family Puzzle Marathon.

Calendar image by Zawesome, distributed under CCL.

Great Packing Trick

Holidays are over and right now is about time to pack decorations into the boxes and shelve them somewhere for 11 long months. Assume that you have 40 identical plastic Christmas baubles that you carefully placed into a flat box like the one sketched below (top view). They fit tightly inside this box.

Suddenly you find another bauble from the same set. How to squeeze this bauble into the same box? Box has a height of one bauble, so no layering.

This puzzle is adapted from a Russian-language journal Kvant.
Top image by Chris_J, distributed under CCL.

Your thoughts and ideas accepted any time until midnight on Sunday Janury 22nd(EST), on our Family Puzzle Marathon. They will be hidden till then and everyone who submitted something reasonable will get a puzzle point.

How Long is This Limousine?

This year's Veterans Day parade featured a novelty limousine that sadly was filled with only a few remaining veterans. Two kids were trying to estimate the length of this cool limo. But the limo was moving, albeit steadily. One of the boys decided to walk alongside the moving limo from its back to the front in parade's direction.  He made 30 steps. Then he turned back and walked alongside the limo in the opposite direction. He made 15 steps. Assuming that each step is 2 feet, can we figure out limo's length?

Image from flickr, distributed under CCL.

Answer ideas accepted any time until midnight on Saturday December 3rd (EST), on our Family Puzzle Marathon. They will be hidden till then and everyone who submitted something reasonable will get a puzzle point.

Halloween dilemma: candy or tchotchkes

Halloween is approaching in a few days and you still have not bought any giveaways. You usually try to be thoughtful and buy candy as well as tchotchkes for those with allergies or strict parents.  Last year expecting 300 kids you bought 300 pieces of candy and 300 tcotchkies. You had only 45 candies and 75 tchotchkes left. Indeed 300 trick-o-treaters showed up according to someones count.

What percentage of the trick-o-treaters took both: candy and tchotchkes?
If you expect 400 kids this year, how many of each, candy and tchotchkes, you should buy to not have any left-overs assuming the same percentages of candy-toy preferences as last year?

Image by eszter, distributed under CCL.

Answer ideas accepted any time until midnight on Saturday October 29th (EST), on our Family Puzzle Marathon. They will be hidden till then and everyone who submitted something reasonable will get a puzzle point.

Unguarded Halloween Treats

Halloween evenings are exciting and busy. Your kids are dressed up way in advance and couldn't wait to start trick-o-treating. As soon as first darkness descends, you finally figure our your costume, and get to the streets to walk your kids from house to house making sure candy goes to the pumpkin and not straight into their mouth. But who will stay at home to give away your candy? You decide to leave the giant bowl of candy outside of your front steps. While trick-o-treating with your kids you noticed that this year there are twice as many little kids as older kids walking around. When you return in an hour, the bowl is empty. You are wondering how quickly all the 350 Kit-Kats have gone and how many kids may have stopped by. You are pretty sure little kids took one candy each as they were supervised by their parents. As for the older kids, you suspect that half of them may have snatched two candies. Can you estimate how many kids stopped by your house?

A Working Holiday

This may have happened to you. Take Veterans Day, Martin Luther King Day, Presidents Day - or any other holiday observed by your child's day care but not observed by most of the private companies. If both, you and your spouse, work and you have not arranged for a babysitting, you are facing a puzzling day. Could you manage? Assume that your child sleeps 10 hours at night and naps 2 hours during the day. You and your spouse each need 8 hours of sleep in order to function responsibly. Is it possible for you to split the day so that both, you and your spouse, will each squeeze a full 8 hour working day and split childcare?

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How far would you drive for a family dinner?

April is the time of travel: Passover dinners, Easter brunches, school vacations or just life-is-beautiful-again weekend trips. A friend complained to me that she spent five hours in the car last week, driving to her mother's house and back for a holiday family gathering. On the way there traffic was terrible due to flooding and she averaged only 20 mph. On the way back, it was a little better averaging 30 mph. How far away do you think her mother lives?

This puzzle is adapted from A. Salny's book (Super Smart Super Puzzle Book #2)

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Matzo Balls Puzzle

Who doesn't love chicken soup? How about a special but rare treat of chicken soup with Matzo balls? During the recent Passover celebration my kids were helping me to roll these balls from the Manischewitz Ball Mix. According to the package directions, it was enough to make around 10 balls of diameter 1". We had two packs and I realized that it is not going to be enough as kids wanted to have more than two for everyone. We decided to make the Matzo balls smaller, with 0.5" diameter. Can you help me to estimate how many balls we will end up having?

Submit your answer on our Family Puzzle Marathon Be first to solve three puzzles and get a prize!

White House Easter Egg Roll

Hundreds of lucky kids arrive every year to the White House Easter Egg Roll. Last year, a specially created commission decided to mark every egg with a number in order to keep track of them all. To avoid using ink, single digit stickers were purchased by this committee. All the eggs were marked with a unique number, using one or more stickers, numbers were assigned in an ascending order. For example, three stickers with digits 2, 4 and 5 were used to make 245. The White House Press Secretary was not at liberty to reveal how many eggs in total were used. Do you think the press can figure it out given that the total number of stickers purchased was 2893?

Submit your answer on our Family Puzzle Marathon Be first to solve three puzzles and get a prize!

A Very Advance Reservation

You are waiting for an appointment in the doctor's office and it looks like she is running late. Unfortunately, your iPhone (or Blackberry) battery is out and other than a Fly Fishing Magazine, all are taken. You suddenly become preoccupied with your son's Bar Mitzvah that is still three years ahead, but you need to reserve a place. You are trying to figure out what day of the week his birthday will fall on in 2013. It falls on Thursday this year, 2010. Is it humanly possible to deduce this without a calendar?

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Valentines Puzzle

Three kids prepared beautiful Valentines at school. Each made the same amount. On Sunday morning they sneaked downstairs and decided to surprise their parents and other home inhabitants by preparing a breakfast. They arranged four adult plates around the table and each of the kids put the same amount of his or her Valentines next to each plate. After that each of the kids gave one Valentine to each of his siblings, and everyone in the house ended up with the same amount of Valentines.
How many Valentines kids made at school?

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A Gelt Puzzle

During this week's Hanukkah celebration kids were playing dreidel game with chocolate coins. Some of the coins were wrapped in aa silver color paper, some bronse, and some gold color. When grandmother (who bought all of these 120 coins) asked how many coins of each type kids had, their answers were pretty confusing. Ben said there are 30 silver and 50 bronse coins. Ariel counted 30 gold and 50 bronse, and Ilana 40 gold and 30 silver. How many coins of each type were there, if we know that only one of these kids is old enough to be trusted to count correctly, each of the others made at least one mistake.

Enter your answer on our Family Puzzle Marathon page. Solve three and get a prize!

Homemade Disco Ball

You decide to make a disco ball at home and surprise everyone at the holiday party. You take an old globe, cement glue and you are heading for a dump to find an old mirror that you can break into little pieces. What size and shape mirror you should look for?


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Thanksgiving Table

Around the Thanksgiving table were seated: two fathers and their two sons, two mothers with their son and daughter, one grandmother, one grandfather, one grandson and a 5 year old granddaughter. According to a family tradition, everyone raised one toast to everything he is thankful for. What is the minimum amount of toasts that may have been heard at this table?

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White House State Dinner

Imagine that you have been invited to a White House State Dinner. Or a fancy formal Thanksgiving Dinner. You observe the exquisite plate setting in front of you and realize that you have no idea with which of the two spoons you are expected to touch the pre-dinner sorbet (palate cleanser).



You are desperately trying not to reveal your ignorance to a very attractive person sitting across the table from you. So, you decide to quickly ask a person to your right or a person to your left, neither of whom have been served the sorbet yet. The problem is that you have been informed that one of the people that is sitting right next to you is a chronic liar. But you do not know which one. What one brief question can you ask from either of your neighbors, that will clarify the spoon approach for you?

Submit your answer on our Family Puzzle Marathon site. Solve three puzzles and get a prize!

A Golden Dress

Puzzles are everywhere. They come in a teacher's note from school, in a form of decision about renewing your fringe benefits or just simply stare at you from a shop's window. Believe it or not! One department store's Holiday decorated window claimed: "Great dress is worth its weight in gold or silver." I was driving by, so not sure I got all the little details right. But the beautiful, T-shirt style, holiday dress was there, sparkling behind the ad. How expensive do you think this dress may be? The ad can't lie, right?

Submit your answer on our Family Puzzle Marathon site. Solve three puzzles and get a prize!

Rosh Hashana Puzzle

Jewish New Year Holiday, Rosh Hashana, is celebrated with apples and honey. If there are 10 apples in a basket, how you divide them equally among 10 people at the table without using a knife, so that one apple still stays in the basket?

Submit your answer on our Family Puzzle Marathon site. Solve three puzzles and get a prize!

Party Dilemma

I am organizing a birthday party for my husband and trying to figure out seating arrangement. If I would split all the guests across two long tables, one person will be left out. If I would seat all the guests in three big tables, one person will still be left out. Arranging for four equal tables, there still be one person left out. If I set five tables, four people will be left out. Six tables - one person left out. Finally, I see that splitting all the guests across seven tables will work perfectly. How many guests are invited to this party?