Harder Riddles

The digits 1, 2, 3, 4, 5, 6, 7, 8, and 9 must be put in the depicted square, in such a way that the sums of the numbers in each row, column, and diagonal are equal.

In a contest, four fruits (an apple, a banana, an orange, and a pear) have been placed in four closed boxes (one fruit per box). People may guess which fruit is in which box. 123 people participate in the contest. When the boxes are opened, it turns out that 43 people have guessed none of the fruits correctly, 39 people have guessed one fruit correctly, and 31 people have guessed two fruits correctly.

General Gasslefield, accused of high treason, is sentenced to death by the court-martial. He is allowed to make a final statement, after which he will be shot if the statement is false or will be hung if the statement is true. Gasslefield makes his final statement and is released.

The equation shown below is not correct:

A long, long time ago, two Egyptian camel drivers were fighting for the hand of the daughter of the sheik of Abbudzjabbu. The sheik, who liked neither of these men to become the future husband of his daughter, came up with a clever plan: a race would determine who of the two men would be allowed to marry his daughter. And so the sheik organized a camel race. Both camel drivers had to travel from Cairo to Abbudzjabbu, and the one whose camel would arrive last in Abbudzjabbu, would be allowed to marry the sheik's daughter.
The two camel drivers, realizing that this could become a rather lengthy expedition, finally decided to consult the Wise Man of their village. Arrived there, they explained him the situation, upon which the Wise Man raised his cane and spoke four wise words. Relieved, the two camel drivers left his tent: they were ready for the contest!

A piece of paper of size 5 by 5 with two blunted corners should be divided into no more than two pieces (i.e. just one cut in total) and be rearranged into size 6 by 4 as shown in the figure below.

A boy leaves home in the morning to go to school. At the moment he leaves the house he looks at the clock in the mirror. The clock has no number indication and for this reason the boy makes a mistake in interpreting the time (mirror-image). Just assuming the clock must be out of order, the boy cycles to school, where he arrives after twenty minutes. At that moment the clock at school shows a time that is two and a half hours later than the time that the boy saw on the clock at home.

The numbers 1, 2, 3, 4, 5, 6, 7, 8, and 9 must be put in the depicted triangle, in such a way that the sums of the numbers on each side are equal.

Consider the figures below. Both triangular figures have been built up from the same four parts. The parts with the same color have exactly the same shape and size! They are only moved around, which resulted in an appearing area in the lower figure, marked with a question mark ('?').

In front of you are 10 bags, filled with marbles. The number of marbles in each bag differs, but all bags contain ten marbles or more. Nine of the ten bags only contain marbles of 10 grams each. One bag only contains marbles of 9 grams. In addition, you have a balance which can weigh in grams accurate, and you are allowed to use it only once (i.e. weigh a single time).

The numbers 1 up to and including 8 must be put in the circles of the depicted net. However, numbers in neighbouring circles must differ more than 1. So, for example, circles connected to a circle with a 4 may not contain a 3 or a 5.

Nine dots are placed in three rows of each three dots, as shown in the picture. These nine dots must be connected by four straight, connected lines (i.e. without 'lifting up the pen' in between).

Given the following figure:

The numbers 16, 18, 20, 22, 24, 26, 28, 28, 32, and 36 need to be filled in in the circles of the figure, in such a way that the sum of numbers of each line amounts to 100.

World explorer Stan the Man is on a dangerous adventure in the jungle. Suddenly an extremely poisonous snake bites him. Luckily he has his medicines with him against this deadly snake poison: two bottles, labeled A en B, containing three pills each. Exactly three times, with an interval of 2 hours, he needs to swallow simultaneously both a pill A and a pill B. In a rush he takes a pill from bottle A and then shakes a pill from bottle B with it... But unfortunately two pills B fall from the bottle and they look completely identical to pill A. He cannot tell which pill was A and which two are B pills... Stan is desperate: if he doesn't take the pills exactly as prescribed, it will be fatal.

In the additions below, all digits have been replaced by letters. Equal letters represent equal digits and different letters represent different digits.

    RE + MI = FA
    DO + SI = MI
    LA + SI = SOL

Every day, Fred takes the train to travel from his work back to Alkmaar, his place of residence. Usually, he arrives at the station of Alkmaar at six o'clock, and exactly at that moment he is picked up by his wife by car. Yesterday evening, Fred took an earlier train, without informing his wife, and therefore he already was at the station of Alkmaar at five o'clock. He decided to walk part of the way to meet his wife. When he met the car with his wife, he drove home with her. In this way, they were home ten minutes earlier than normal. Fred's wife always drives the entire way between home and station at the same constant speed.

In addition shown below, each of the letters A, B, C, D, and E represents one of the digits from 1 up to 5 (equal letters represent equal digits and different letters represent different digits). The first and last digits of the sum are given.

    ABCDE
    DABEC
    EAABC
    ACDAE
    ----- +
    9CBA0

An old farmer died and left 17 cows to his three sons. In his will, the farmer stated that his oldest son should get ¹/₂, his middle son should get ¹/₃, and his youngest son should get ¹/₉ of all the cows. The sons, who did not want to end up with half cows, sat for days trying to figure out how many cows each of them should get.

One day, their neighbour came by to see how they were doing after their father's death. The three sons told him their problem. After thinking for a while, the neighbour said: "I'll be right back!" He went away, and when he came back, the three sons could divide the cows according to their father's will, and in such a way that each of them got a whole number of cows.

A carpet of size 10 by 10 meters should be placed in a room of size 12 by 9 meters. In the center of the room, there is an aquarium of size 8 by 1 meters (see the figure below). The carpet should be cut into no more than two pieces (i.e. one cut in total).

Have a look at the house plan at the right hand side, with five rooms and sixteen doors in total. The intention is to make a run through the rooms and pass each of the sixteen doors exactly once.

2 9 3 1 8 4 3 6 5 7

Peasant Marian wants to buy new chickens, pigs, and horses. A new chicken costs 50 eurocents, a pig 3 euros, and a horse 10 euros. Peasant Marian has 100 euros with which she wants to buy exactly 100 animals, but in such a way that she has at least one of each kind of animal.

It's always 1 to 6,
it's always 15 to 20,
it's always 5,
but it's never 21,
unless it's flying.

Given the following magic square:

Fill in the magic square, in such a way that the sum of the numbers in each row (horizontally, vertically, and diagonally) is 264, even if you hold the square upside down. You are only allowed to use the digits 1, 6, 8, and 9, and each number may appear only once in the square.

You have a painting with a string attached to it. The string is attached to the upper two corners of the painting. In the wall there are two nails, horizontally next to each other. The string must be hung on the nails in such a way that the painting falls down if any of the two nails is pulled out of the wall. The painting must hang under the nails and must hang on the string.

There are three houses (A, B, and C) and three utilities (gas (G), water (W), and electricity (E)). Each house must get a direct, uninterrupted connection to each utility, but the various connections should not cross each other.

The numbers 1 up to 12 must be placed in the circles of the star shown on the right. The sums of the numbers in each row, and the sum of the numbers in the six outer circles of the star, must be equal 26.

In the figure on the right, you can fill in each of the sixteen numbers 1 up to 16, in such a way that the sum of the numbers in each of the seven rows is 29.