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

Find out the number of circles in the given picture having Illusion

How many circles do you see?

Asked by Neha on 20 Apr 2021


Two guards were guarding the camp.Guard-1 was looking towards the south to make sure no threat is coming from the road.Guard-2 was looking at the north to make sure no threat is coming from the top. Suddenly Guard-1 ask the Guard-2 why he is smiling?How Guard-1 knows that Guard-2 is smiling?

Asked by Neha on 30 May 2023

What will be the best approach to finding all the prime numbers less than 75 that leave an odd reminder when we divide them with 5?

Asked by Neha on 12 Jul 2021


In The 1st month of this year(the year 2013), I noticed that the date 13-1-13 (13 January 2013) is special.

This date is special as:

Date * Month = Year.

Can you figure out which year of this century has a maximum number of such dates?

Asked by Neha on 14 Aug 2024

1 + 9 + 8 = ?
considering, 28 + 8 + 92 = 10

Asked by Neha on 03 Aug 2021

You see a mathematical expression in the picture. Can you think of a movie that this expression refers to?

Movie in Maths

Asked by Neha on 05 Aug 2021


A man always keeps a spare tyre in his car. To make full use of all the five tyres, he changes the tyres in a manner that for a distance of 1, 00,000 km, each of them runs the same distance.

Can you calculate the distance travelled by each tyre on that journey?

Asked by Neha on 14 Sep 2023

There are seven sisters in a house in a village where there is no electricity or any gadget.

Sister-1: Reading Novel
Sister-2: Cooking
Sister-3: Playing Chess
Sister-4: Playing Sudoku
Sister-5: Washing clothes
Sister-6: Gardening

what is Sister-7 doing ?

Asked by Neha on 26 Jan 2025

Two-person want to cross a river. Only one boat is present on the riverside that can carry only one person at a time.

However, they still manage to cross the river. How is it possible?

Asked by Neha on 18 Nov 2023


Why are televisions attracted to people?

Asked by Neha on 14 Jan 2024

Hot Articles

Amazing Facts

Gambling

In Canada, a mathematical puzzle must be solved in order to win the lottery to classify it as a “game of skill” not gambling.