#### Math Puzzles Question & Answers

# Puzzle : Bridge Crossing

#### Additional Details

Jim, Jeanne, Louis and Anne wants to cross the bridge at night. They have only one torch light with them. Only two can cross the bridge at a time. They need torch light to cross the bridge. Each of them walks at a different speed. Jim needs 1 minute, Jeanne needs 2 minutes, Louis needs 5 minutes and Anne needs 10 minutes. A pair must walk together at the rate of the slower person. How these people can cross the bridge within 17 minutes?

First Jim and Jeanne walks across the bridge, it takes 2 minutes.

Jim walks back with the torch light, which takes 1 minute.

Then Louis and Anne walk on the bridge, which takes 10 minutes.

Jeanne comes back with the torch light, it takes 2 minutes.

Finally Jim and Jeanne walks across the bridge, which takes 2 minutes.

Total = 2 + 1 + 10 + 2 + 2 = 17 minutes

Subject: Math Puzzles

- Related Questions

Which number multiplied by itself will give the output as 12345678987654321 ?

11 * 11 = 121

111 * 111 = 12321

what we observe is that the square of the number follows a pattern: 2 1's gives 121. 3 1's gives 12321.

so to get 12345678987654321 we need to get square of 9 1's(111,111,111).

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Subject: Math PuzzlesWhat 5 - digit number has the following features :

If we put the numeral 1 at the beginning, we get a number three times smaller than if we put the numeral 1 at the end of the number?

Let the 5 digit number be represented by abcde.

Then the 6 digit number, 1abcde x 3 = abcde1 (another 6 digit number)

Now let Y = abcde

Then (100000 + Y) x 3 = (Y x 10) + 1

300000 + 3Y = 10Y + 1

7Y = 299999

Y = 299999 ÷ 7 = 42857

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Subject: Math PuzzlesArrange four nines(9) and a one(1) and only one mathematical symbol to make it equal to 100 ?

199 - 99 = 100

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Subject: Math Puzzles

In a Certain Country of 5 = 3. If the same proportion holds, what is the value of of 10 ?

A) 4 | B) 6 |

C) 8 | D) 10 |

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Subject: Math PuzzlesReplace each letter for a unique digit so that the equation is correct

(1+9+6+8+3) x (1+9+6+8+3) x (1+9+6+8+3) = 19683

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Subject: Math Puzzles