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 Riddles

I am a mother. However, I never give birth.

I am a father. However, I never nurse my children.

Wandering is not possible for me, but standing still happens occurs rarely.

Who am I?

Asked by Neha on 30 Oct 2024


How many points are there on the globe where, by walking one mile south, then one mile east and then one mile north, you would reach the place where you started?

Asked by Neha on 21 Apr 2022

Below, you will find the mathematical proof that 10 equals 9.99999?. But is that possible or there is something wrong about it? Can you find the error?

x = 9.999999...
10x = 99.999999...
10x - x = 90
9x = 90
x = 10

Asked by Neha on 27 Aug 2021


A man is trapped in a room. The room has only two possible exits doors. Through the first door there is a room constructed from magnifying glass. The blazing hot sun instantly fries anything or anyone that enters. Through the second door there is a fire-breathing dragon. How does the man escape?

Asked by Neha on 09 Jan 2021

Bopanna was working on a murder case when he received a message about the location of the murder weapon.
The message was encrypted as below.

"deb mitciv eht edisni neddih si nopaew redrum ehT"

Tell me the location of the murder weapon.

Asked by Neha on 04 Jan 2026

An American nightclub called 'The Coconut Grove' had a terrible fire in which over 400 people died. A simple design flaw in the building led to a high death toll. Subsequently, regulations were changed to ensure that all public buildings throughout the country eliminated this one detail, which proved deadly. What was it?

Asked by Neha on 05 Oct 2024


What breaks yet never falls, and what falls yet never breaks?

Asked by Neha on 09 Mar 2025

Find the hidden tiger in the given optical illusion ?

Find the Tiger

Asked by Neha on 13 Jan 2021

Can you find the next number in the below sequence
3 , 7 , 10 , 11 , 12 , 17 ?

Asked by Neha on 04 Mar 2025


What part of the chicken has the most feathers?

Asked by Neha on 19 Jul 2025

Hot Articles

Amazing Facts

Gamers

In 2011, people playing Foldit, an online puzzle game about protein folding, resolved the structure of an enzyme that causes an Aids-like disease in monkeys. Researchers had been working on the problem for 13 years. The gamers solved it in three weeks.