# Thread: how we will have 5 L?

1. ## how we will have 5 L?

There is three bottles, the first can carry only 10L,the second 7L, the third 3L.
The first is full while the other two are empty...how can we have 5 L only in the first one??? without using any instrument.

2. Originally Posted by lebanon
There is three bottles, the first can carry only 10L,the second 7L, the third 3L.
The first is full while the other two are empty...how can we have 5 L only in the first one??? without using any instrument.
Put 6L in bottle that carry 7L ( put two time 3L in bottle that carry 3 L and than in 7L bottle every time ) now you have 4L in 10L-bottle and 6L in 7L-bottle Now fill the 3L bottle with water from 10L bottle

now you have 1L in 10L - bottle, 3L in 3L - bottle and 6L in 7L-bottle now take 1L from 3L and put it in 7L , now 7L - bottle is full 3L -bottle has 2L and 10L - bottle has 1 L. Now empty the 3L - bottle and refill it with 7L bottle now you have:

4L in 7L bottle, 1L in 10L bottle and 3L in 3L bottle. You know the rest

3. Hello, lebanon!

There are three bottles $\displaystyle A,B,C$ with capacities 10L, 7L, and 3L, respectively.
$\displaystyle A$ is full; the other two are empty.
Get exactly 5L in $\displaystyle A.$

We have:
Code:
      *----*
|::::|
|::::|    *   *
|::::|    |   |
|::::|    |   |
|::::|    |   |     *   *
|::::|    |   |     |   |
|:10:|    | 0 |     | 0 |
*----*    *---*     *---*
A         B         C

Pour A into C.
Code:
      *    *
|    |
|----|    *   *
|::::|    |   |
|::::|    |   |
|::::|    |   |     *---*
|::::|    |   |     |:::|
|::7:|    | 0 |     |:3:|
*----*    *---*     *---*
A         B         C

Pour C into B.
Code:
      *    *
|    |
|----|    *   *
|::::|    |   |
|::::|    |   |
|::::|    |---|     *   *
|::::|    |:::|     |   |
|::7:|    |:3:|     | 0 |
*----*    *---*     *---*
A         B         C

Pour A into C
Code:
      *    *
|    |
|    |    *   *
|    |    |   |
|----|    |   |
|::::|    |---|     *---*
|::::|    |:::|     |:::|
|::4:|    |:3:|     |:3:|
*----*    *---*     *---*
A         B         C

Pour C into B.
Code:
      *    *
|    |
|    |    *   *
|    |    |---|
|----|    |:::|
|::::|    |:::|     *   *
|::::|    |:::|     |   |
|::4:|    |:6:|     | 0 |
*----*    *---*     *---*
A         B         C

Pour A into C.
Code:
      *    *
|    |
|    |    *   *
|    |    |---|
|    |    |:::|
|    |    |:::|     *---*
|----|    |:::|     |:::|
|::1:|    |:6:|     |:3:|
*----*    *---*     *---*
A         B         C

Pour C into B.
Code:
      *    *
|    |
|    |    *---*
|    |    |:::|
|    |    |:::|
|    |    |:::|     *   *
|----|    |:::|     |---|
|::1:|    |:7:|     |:2:|
*----*    *---*     *---*
A         B         C

Pour B into A.
Code:
      *    *
|----|
|::::|    *   *
|::::|    |   |
|::::|    |   |
|::::|    |   |     *   *
|::::|    |   |     |---|
|::8:|    | 0 |     |:2:|
*----*    *---*     *---*
A         B         C

Pour C into B.
Code:
      *    *
|----|
|::::|    *   *
|::::|    |   |
|::::|    |   |
|::::|    |   |     *   *
|::::|    |---|     |   |
|::8:|    |:2:|     | 0 |
*----*    *---*     *---*
A         B         C

Pour A into C.
Code:
      *    *
|    |
|    |    *   *
|    |    |   |
|----|    |   |
|::::|    |   |     *---*
|::::|    |---|     |:::|
|::5:|    |:2:|     |:3:|
*----*    *---*     *---*
A         B         C

There!