Tips ,Tricks and Shortcuts of number system
A Number System is the mathematical notation for representing numbers using digits or other symbols in a manner.


A Number System is the mathematical notation for representing numbers using digits or other symbols in a manner.


For example : Question : π is rational number or irrational.
Solution: Yes, π is rational number as it can be written in qp form.
Question 1 Which one of the following is not a prime number?
Options
A. 51
B. 23
C. 17
D. 11
Solution: 51 is divisible by 17. So, it is not a prime number.
Correct option: A
Question 2. How many prime numbers are there from 1 to 50?
Options
A. 20
B. 15
C. 21
D. 25
Solution: Prime numbers less than 50 are:
2, 3, 5, 7, 11, 13, 17, 19, 23, 29, 31, 37, 41, 43, 47
Correct option: B
Question 3 1198 * 1198 = ?
Options
A. 1435204
B. 1432504
C. 1453204
D. 1435024
Solution: (1198)²
(1200 – 2)²
We can use the identity: (a-b)²= a² + b² – 2ab
(1200)² + 2² – 2 * 1200 * 2
1440000 + 4 – 4800
1435204
Correct option: A
Question 4. The sum of first five prime numbers is:
Options
A. 20
B. 28
C. 30
D. 25
Solution: Sum of first five prime numbers is = 2+3+5+7+11 = 28
Correct option: B
Question 5. If x and y are odd numbers, then which of the following is even numbers?
Options
A. x + y
B. xy
C. x – y
D. xy + 2
Solution: The sum of two odd number is always even. So, x + y is even.
Correct option: A
Read Also – How to solve number system problems Quickly

Super
Thank you Akhil,
We hope it may help you out
Where is other questions of number and system
Hi Jayprakash,
This is just Tips and Tricks Page and to give you guys basic idea about how to apply those tricks we put several questions here.
To access more Questions, you can find it on Particular Companies Dashboards.
Thanks