All Puzzles

John and Jacob are on the two opposite banks of a river. They both have a rowing boat.
They both start at the same time towards the opposite bank. They pass each other at 180 meters from the bank where john departed. When reaching the opposite bank, they both take a rest for the same amount of time before they return. On the way back, they pass each other at 100 meters from the bank from where John returned.
John and Jacob both row with a constant speed, but Jacob rows faster.
How wide is the river?
View SolutionSubmit Solution 40 views
 1 answers
 0 votes

Imagine a disk spinning like a record player turn table. Half of the disk is black and the other is white. Assume you have an unlimited number of colour sensors. How many sensors would you have to place around the disk to determine the direction the disk is spinning? Where would they be placed?
View SolutionSubmit Solution 54 views
 1 answers
 0 votes

Peasant John wants to buy new chickens, pigs, and horses. A new chicken costs 50 euro cents, a pig 3 euros, and a horse 10 euros. Peasant John has 100 euros with which he wants to buy exactly 100 animals, but in such a way, that she has at least one of each kind of animal.
How many animals must peasant John buy of each kind?
View SolutionSubmit Solution 103 views
 2 answers
 0 votes

Jacob & John have two children. The probability that the first child is a girl is 50%. The probability that the second child is a girl is also 50%. Jacob & John tell you that they have a daughter.
What is the probability that their other child is also a girl?
View SolutionSubmit Solution 133 views
 1 answers
 0 votes

A school bus travels from Los Vegas to Lo Angels. There are four children in the bus. Each child has four backpacks with him. There are four dogs sitting in each backpack. Every dog has four puppies with her. All these dogs have four legs, with four toes at each leg.
What is the total number of toes in the bus?
View SolutionSubmit Solution 159 views
 2 answers
 0 votes

Calculate below as fast as you can, using only mental arithmetic (Without pen, paper, or a calculator!).
Take 1000 and add 40.
Add 1000.
Add 30 and then add 1000.
Add 20.
Add 1000 and then add 10.What is the result of this calculation?
View SolutionSubmit Solution 230 views
 2 answers
 1 votes

There is a tree 20 feet high, with a circumference of 3 feet. A vine starts at the base of the tree and winds around the tree 7 times before reaching the top. How long is the vine?
View SolutionSubmit Solution 213 views
 1 answers
 0 votes

You are given “n” coins of denominations 1, 0.5, 0.25, 0.1, 0.05 and 0.01 (6n coins altogether). You are then asked to choose n out of these 6n coins that sum up to exactly 1. What is the smallest n for which this is impossible?
View SolutionSubmit Solution 199 views
 1 answers
 0 votes

A confused bank teller transposed the dollars and cents when he cashed a cheque for Ms Denial, giving her dollars instead of cents and cents instead of dollars. After buying a newspaper for 50 cents, Ms Denial noticed that she had left exactly three times as much as the original cheque. What was the amount of the cheque ?
View SolutionSubmit Solution 141 views
 1 answers
 0 votes