some times in quantitative aptitude test finding out cube root can turn in to massive headache , normally the question will be about finding square root of integers and six digits. This technique wont work with numbers more than six digits or which is not a perfect cube. This can really save some time for you.

Ok first lets take an example, say ,

The answer is 49, lets see how to find it in less than 20 seconds. To solve this you should know cube root of first ten numbers.

N0 Cube

1 1

2 8

3 27

4 64

5 125

6 216

7 343

8 512

9 729

10 1000

ok, now lets start,

first divide the above number in to two, Start with the last three numbers, it will be your first half and the remaining number will be your other half, see the example below.

Step 3: now, consider the first part 649 , the three digit number ends with 9, in the above table we can see that cube root of 9 gives a answer that ends with

combining step 2 and 3 we get

Thats it,

Ok first lets take an example, say ,

**117649**The answer is 49, lets see how to find it in less than 20 seconds. To solve this you should know cube root of first ten numbers.

N0 Cube

1 1

2 8

3 27

4 64

5 125

6 216

7 343

8 512

9 729

10 1000

ok, now lets start,

__Step 1:__in the above table we can see the cube root of first 10 numbers, The question is to find the cube root of**117649**

first divide the above number in to two, Start with the last three numbers, it will be your first half and the remaining number will be your other half, see the example below.

**117 | 649****now , consider the second part (i,e) 117 , see where it lies in the above table, in the above table it lies between 4 and 5, now we have to take the lowest number of these two (i,e)**__Step 2:__**4**Step 3: now, consider the first part 649 , the three digit number ends with 9, in the above table we can see that cube root of 9 gives a answer that ends with

**9 , therefore 9 is the second answer**combining step 2 and 3 we get

**49, which is the final answer**Thats it,

## 0 comments:

## Post a Comment