Short Tricks to Find Cube and Cube Roots for Bank Exam 2020

Have been preparing for banking exams for the last 1+ years, concepts are all clear but not able to clear even the prelims exam. Are you one of those candidates facing this challenge.? There are a lot of candidates who can score well in both the English and Reasoning section still not able to get into the final list only because of the QA section. Have you ever wondered about what is going against you while attempting the QA section even though you are master in each and every concept? It isn’t because you are getting slow while doing the calculation.? If the answer is a ‘Yes’, then this article is going to be game-changer in your career. Check here for Short Tricks to find Cube and Cube Roots

Most times, candidates repeat this mistake of mastering every concept but ignore the timing. They would be able to solve even the highest level problem. But as we all know, timing is the key in the preliminary section of the banking tests. You will be asked to solve 35 questions in just 20 minutes. So, in order to clear the high-cutoffs, you have to attempt the maximum number of questions with minimum time. The best way to achieve this time is by reducing the calculation speed by adapting various tips and tricks. This article is about such tricks for finding cube and cube root of numbers. These short tricks will help you calculate cube and cube roots of numbers literally in a glimpse.

Cubes of Numbers

Short trick to find Cube of a two-digit number

The basic formula for finding  the cube root of a number is (a+b)³ = a³ +3a²b+3ab²+b³ 

We are using this same formula for calculation but in an easier method

Example :

Step 1.

Find the cube of individual numbers

Step  2     

Multiply the square of the first number with the second number, then the square of the second number with the first number.

                                                                   64       32        16       8

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 Step 3

Double the value of the solutions in the second step and add it to the same value. ie, Double of 32 =64 and double of 16=32

Step 4

Arrange the results in the corresponding order by taking only the digits on the units place and the digit on the tens place is added to the next number.

 Daily Practice Quiz for Bank Exams 2020

Cube of three-digit numbers

We use the formula, (a+b)³ = a³ +3a²b+3ab²+b³  

Answer:  1092727

 Short Trick to find Cube root of a number

Step 1

Find the unit digit of the cube root number

Example:

There are some tricks to find the cube root easily.

• If the last digit of the given number is 1, the unit digit of cube root will  be1
• If the last digit of the given number is 8, the unit digit of cube root will be 2
• If the last digit of the given number is 7, the unit digit of cube root will be 3
• If the last digit of the given number is 4, the unit digit of cube root will be 4
• If the last digit of the given number is 5, the unit digit of cube root will be 5
• If the last digit of the given number is 6, the unit digit of cube root will be 6
• If the last digit of the given number is 3, the unit digit of cube root will be 7
• If the last digit of the given number is 2, the unit digit of cube root will be 8
• If the last digit of the given number is 9, the unit digit of cube root will be 9

Here the last digit of the number is 2, so the unit digit of cube root will be 8.

Step 2

Divide the given number into 2 groups, last 3 digits are taken as one group and all other digits are taken as 2nd group.

58    472

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Step 3

Find the nearest cube of the first group ie, 58

The nearest cube is 27 ie, the number on the ten’s place is 3.

Step 4

Combine the numbers on the ten’s and one’s place. ie, 38

Answer :

Example 2

Step 1: The last digit is 3, so the unit digit of the cube root is7.

Step 2: Grouping the given number

 103                      823

Step 3: The nearest cube is 64, therefore tens place digit is 4.

Step 4 :

Answer

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