Tag: math & puzzles

The sum of ages of 5 children, born at the intervals of 3 years each, is 50 years. What is the age of the youngest child?

How many squares are there on a chessboard?

A train travels a certain distance taking 7 hrs in forward journey, during the return journey increased speed 12km/hr and the time taken is 5 hrs.What is the distance traveled on one side?

In the middle of a round pool lies a beautiful water-lily. The water-lily doubles in size every day. After exactly 20 days the complete pool will be covered by the lily. After how many days will half of the pool be covered by the water-lily?

A man decides to buy a nice horse. He pays $60 for it, and he is very content with the strong animal. After a year, the value of the horse has increased to $70 and he decides to sell the horse. But already a few days later he regrets his decision to sell the beautiful horse, and he buys it again. Unfortunately he has to pay $80 to get it back, so he loses $10. After another year of owning the horse, he finally decides to sell the horse for $90. What is the overall profit the man makes?

You have three bags, each containing two marbles. Bag A contains two white marbles, Bag B contains two black marbles, and Bag C contains one white marble and one black marble. You pick a random bag and take out one marble. It is a white marble. What is the probability that the remaining marble from the same bag is also white?

There are five gears connected in a row, the first one is connected to the second one, the second one is connected to the third one, and so on. If the first gear is rotating clockwise what direction is the fifth gear turning?

There are five gears connected in a row, the first one is connected to the second one, the second one is connected to the third one, and so on. How much faster would the last gear be if the second gear was twice the size of the first gear, and all the other gears were the same size as the first gear? Assume that the first gear is rotating at the rate of 50 revolutions per minute(rpm).

At a restaurant downtown, Mr. Red, Mr. Blue, and Mr. White meet for lunch. They are wearing either a red, blue, or white shirt. Mr. Blue says, "Hey, did you notice we are all wearing different colored shirts from our names?" The man wearing the white shirt says, "Wow, Mr. Blue, that's right!" Can you tell the colour of Mr. Blue's shirt?

The journey from Lonavla to Pune via local train takes 80 minutes. The return journey, however, takes 1 hour and 20 minutes. The route for both the journeys are the same. Is this possible? (True for yes, false for no).