Tips and Tricks and Shortcuts for Coding and Number Series

Number Series

Number series is a series where the candidate will have to observe and guess the hidden code of two or more sets of numbers.
Now the main important thing is to solve the questions. Before solving the questions lets have a look at the Solved Questions that will help us in a better understanding of questions.

Tips and Tricks and Shortcuts for Coding and Number Series/ Different Number Series

• Series of Perfect Square

A series on Perfect Square is most of the times based on the perfect squares of number in a generic order or generally one number is missing in this type of series

Example:- 144,169,289,324?
144= 12² , 169², 289= 17², 324= 18²

• Perfect Cube Series

Based on the cubes of numbers in a particular order and one of the numbers is missing in the series.

Example:- 343, 512, 729, 1000?
7³, 8³, 9³, 10³

• Geometric Series

It is based on either descending or ascending order of numbers and each successive number is obtained by dividing or multiplying the previous number by a specific number.

Example:- 5, 45, 405, 3645?
Sol:5 x 9 = 45, 45 x 9 = 405, 405 x 9 = 3645, 3645 x 9 = 32805.

• Arithmetic Series

It consists of a series in which the next term is obtained by adding/subtracting a constant number to its previous term. Example: 4, 9, 14, 19, 24, 29, 34 in which the number to be added to get the new number is 5. Now, we get an arithmetic sequence 2,3,4,5.

• Two Type Series

Question 1

In a certain code, the number 12345 is coded as 36936. What will be the code for the number 99325?

A) 99966
B) 37649
C) 78356
D)33965

Answer: A

Explanation:

If we take 1 and multiply it by 3 and repeat the same with all the other digits of the first number, we will have:

• 1 gives 3
• 2 gives 6
• 3 gives 9
• 4 gives 12 = 1+2 = 3
• And 5 gives 15 = 1+5 = 6

Here, the new number we will get is 36936. Now, this was the main trick so we will apply the same for 99325.

• 9 when multiplied by 3, will give 27 = 2+7 = 9.
• Also, 3 when multiplied by 3, will give 9.
• And 2 will similarly yield 6.
• 5 will give 15 = 1+5 = 6

New number = 99966

Question 2

Look at series 4 , 2, 1, \frac{1}{2} \ , \frac{1}{4} \ …. what would come next?

A) \frac{1}{3} \
B) \frac{1}{8} \
C) \frac{1}{16} \
D) \frac{2}{16} \

Answer: B

Explanation:

\frac{4}{2} = 2
\frac{2}{2} = 1
\frac{1}{2} = \frac{1}{2}
\frac{\frac{1}{2}}{2} \ = \frac{1}{4}
\frac{\frac{1}{4}}{2} = \frac{1}{8} and so on.