unit place of 4137^754
Answers
Answer:
Step-by-step explanation:
By cyclicity after every 4 powers of a no. ending with 7, unit digit =1.
Hence unit digit of 4137^752=1
unit digit of 4137^753=1×7=7
unit digit of 4137^754=unit digit of 7×7= 9
Given:
A number in exponential form 4137^754.
To Find:
The units digit of the above number.
Solution:
1. The given number is
2. The number can be also written as,
=>,
3. The units digit of the number is 0. ( All the powers of the numbers ending with 0, have 0 as their units digit, except for power 0 which ends with 1 ).
4. The units digit value of 7^n is,
- 7 for 4n+1 type values, (n can vary from 0 to infinite)
- 9 for 4n+2 type values,
- 3 for 4n+3 type values,
- 1 for 4n type values.
For example, the units digit of 7^4 is 3 as 4 can be also written as 4(1).
5. Using the property mentioned above the units digit of the number can be found,
=> 754 = 4(188) + 2, ( 4n + 2 type value)
=> Therefore, the units digit is 9.
=> Hence the units digit of the number is 0 + 9 = 9.
Therefore, the units digit of the number 4137^754 is 9.