A father and son work in the same factory. The father takes 30 minutes to walk to his factory and the son is able to cover the same distance in only 20 minutes. If the father were to leave the house 5 minutes earlier, how soon would his son catch up with his father?
There are 4 clocks in a room. One gains a minute every hour. Another loses a minute every hour. One runs backward at normal speed. The fourth always keeps the correct time. At 7:03 today, they all showed the same time, which was correct. When will this happen again?
“Every day at noon,” Lucas said, “a ship leaves Le Havre for New York and another ship leaves New York for Le Havre. The trip lasts 7 days and 7 nights. How many New York-Le Havre ships will the ship leaving Le Havre today meet during its journey to New York?
There are two planes headed towards each other. One plane is traveling at 15 kilometers per minute, and the other is traveling at 10 kilometers per minute. Assuming that the planes are exactly 1000 kilometers apart, what distance will be between them one minute before they meet?
Three missionaries and three cannibals want to get to the other side of a river. There is a small boat, which can fit only two. To prevent a tragedy, there can never be more cannibals than missionaries together. How can all the cannibals and missionaries cross the river safely ?
Two boys, Tom and Harry, are running a 100 meter race. The first time they race Tom beats Harry by 5 meters. To make things fair, the next time they race Tom stands 5 meters behind the starting line. Who wins the second race (assuming they run at the same speed as the first race)?
A contractor is doing work for 7 days at your home. You have a gold bar that is worth $7000. You need to pay him $1000 every day and $7000 in total. You have to pay him in gold by using the gold bar. How can you pay him $1000 worth of gold everyday by cutting the gold bar only twice?
Nancy and Audrey set out to cover a certain distance by foot. Nancy walks half the distance and runs half the distance, but Audrey walks half the time and runs half the time. Nancy and Audrey walk and run at the same rate. Who will reach the destination first (or will it be a tie)?
A book has 500 pages: The 1st page says “Exactly 1 page in this book is false.” The 2nd page says “Exactly 2 pages in this book are false.” … The 500th page says “Exactly 500 pages in this book are false.” Can any of the pages be true?
There is a party of 100 politicians. All of them are either honest or liars. You walk in knowing two things: At least one of them is honest. If you take any two politicians, at least one of them is a liar. From this information, can you know how many are liars and how many are honest?
A man recently bought two aeroplanes, but afterwards found that they would not answer the purpose for which he wanted them. So he sold them for $600 each, making a loss of 20 per cent on one machine and a profit of 20 per cent on the other. Did he make a profit on the whole transaction, or a loss? And how much?
A bathtub has two taps and a plug hole. The cold tap on its own fills the bathtub in 18 minutes. The hot one on its own fills the bathtub in 15 minutes. The plug hole can drain the bathtub in 10 minutes with the taps off. How long will the bathtub take to fill if both taps are turned on and the plug left out?
You must buy hundred eggs with hundred cents. There are three types of eggs and you will need to buy all three types of eggs. Goose eggs must be bought in multiples of 20. 1 Chicken egg cost 5 cents 1 Duck egg cost 1 cent 20 Goose eggs cost 1 cent How many chicken, duck and goose eggs do you need to buy?
Each morning Boris walks to school. At one-fourth of the way he passes the machine and tractor station; at one-third of the way, the railroad station. At the machine and tractor station its clock shows 7:30, and at the railroad station its clock shows 7:35. When does Boris leave his house, when does he reach school?
Water lilies grow extremely rapidly. In one pond, a water lily grew so fast that each day it covered a surface area double that of the area it had covered the previous day. At the end of the 30th day, it had covered the pond entirely. How long do you think it will take for two such water lilies to cover the whole pond?
