River Crossing with one Torch

Four people need to cross a rickety bridge at night. Unfortunately, they have only one torch and the bridge is too dangerous to cross without one. The bridge is only strong enough to support two people at a time. Not all people take the same time to cross the bridge. Times for each person: 1 min, 2 mins, 7 mins and 10 mins. What is the shortest time needed for all four of them to cross the bridge?

River Crossing with one Torch




Similar Logic Riddles

In a family supper, a grandfather, a grandmother, two fathers, two mothers, four children, three grandchildren, one brother, two sisters, two sons, two daughters, one daughter-in-law, and one mother-in-law need to sit at a table.

There are only seven chairs available at the place. How many more chairs do they have to borrow so that everyone can sit down together for the suppers if everybody requires a separate chair?

Asked by Neha on 09 Nov 2024


This is a game of Tic-Tac-Toe which you all might have played innumerable times. Here, we are playing with the black and white markers instead. Also, there is a bit change to the rules. The changed rules allow you to play just three times. After the three markers are put by each of the players, you can only slide your marker into an empty square that shares a common wall with the square that the marker is leaving. You can refer to the figure given. If this is the position of the game, the white's next move would be from 6 to 3. Now, whatever the black one does, the white one will move his marker from 5 to 2 and he will have a three in a row. What you have to decide is if both of the players are using a perfect strategy, will the white player (who plays first) always win? Or it will be the black one who will win always? Or every game will be a draw?

Tic Tac Toe Riddle

Asked by Neha on 11 Aug 2026

You are trapped into a death trap by the famous jigsaw killer. As usual, a screen flashes in front of you and explains you the trap game. There are 100 pearls kept in a bowl in front of you and an empty bowl. Among the 100 pearls, 50 are white and 50 are black. You can divide them as you like into the two bowls. Once you are done, you will pull a lever, which will turn the room pitch black. The bowls will move and shuffle around. In the dark, you have to pick up one pearl from any bowl. Once you do that, the room will flood with lights again. If the peral you have in your hand is white, you will be allowed to live, but if the pearl you picked is black, the room will be filled with poisonous gas and you will die. How will divide the pearls to increase your chances of survival?

Asked by Neha on 03 Sep 2024


There is a bag which have 21 blue balls and 23 red balls. You also have 22 red balls outside the bag. Randomly remove two balls from the bag. * If they are of different colors, put the blue one back in the bag. * If they are the same colour, take them out and put a red ball back in the bag. Repeat this until only one ball remains in the bag. What is the color of the sole ball left in the bag ?

Asked by Neha on 13 Mar 2026

Three people check into a hotel. They pay $60 for the rent of the room. After they check-in, the manager realize that the rent for the room is $55. So, he gives $5 to the bellboy and asks him to give it to them. The bellboy thinks that it will be difficult for the three people to share $5 among them and seeking the personal benefit, he pockets $2 and gives the remaining $3 to them.

Now, each person paid $20 and got back $1. In this manner, each of them paid just $19 which totals to the amount of $57. The bellboy has $2 with him and adding them, we get $59. So where is the remaining $1?

Asked by Neha on 02 Aug 2023

Can you find a pattern and the missing number in the series given below?

100, 155, 258,? , 584, 819.

Asked by Neha on 23 Sep 2024


As shown in the image, the nine Dogs are square fenced. By constructing just two square fences can you make sure that two Dogs cannot meet each other without crossing the fence?

Fence the Fencing

Asked by Neha on 09 Mar 2021

In an Art Gallary, When the clock hit 11 am, Artist hung the painting number 30. When it struck 4 pm, he hung painting number 240 and when it struck 7:30 pm, he hung painting number 315.

Can you determine, which painting number will he hang when the time is 9:20 pm?

Asked by Neha on 18 Sep 2025

Today, I celebrated my 32nd birthday but I was born in 1972.
How is this possible?

Asked by Neha on 01 May 2025


The LCD device should be able to tell the right time in the format HH:MM: SS in a 12-hour format. You can refer to the picture to get an idea. The device is a simple "level indicator" which has to be converted into a watch. How will you program it to work?

Asked by Neha on 24 Jun 2026

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Amazing Facts

Out of the Box

The phrase “thinking outside the box” was popularised from the solution to a topographical puzzle involving 9 dots in a box shape.