Aptitude - Square Root and Cube Root - Discussion
Discussion Forum : Square Root and Cube Root - General Questions (Q.No. 4)
4.
1.5625 = ?
Answer: Option
Explanation:
1|1.5625( 1.25
|1
|-------
22| 56
| 44
|-------
245| 1225
| 1225
|-------
| X
|-------
1.5625 = 1.25.
Discussion:
62 comments Page 2 of 7.
Sandhya said:
1 decade ago
sqrt of 1. 5625 = sqrt of [15625/10000].
15625=125*125 ; 10000=100*100.
=125^2 ; =100^2.
sqrt of 15625=[125^2]^ (1/2) ; sqrt of 10000=[100^2]^ (1/2).
Powers get cancelled, therefore = 125/100.
= 1. 25.
15625=125*125 ; 10000=100*100.
=125^2 ; =100^2.
sqrt of 15625=[125^2]^ (1/2) ; sqrt of 10000=[100^2]^ (1/2).
Powers get cancelled, therefore = 125/100.
= 1. 25.
Siva said:
10 years ago
1.25 *1.25.
If the last digits ends with 5 always in both the sides multiply 5*5.
Then in the first digit add one number.
12 + 1 = 13.
Now multiply 12*13 = 156.
This method will be more easy.
If the last digits ends with 5 always in both the sides multiply 5*5.
Then in the first digit add one number.
12 + 1 = 13.
Now multiply 12*13 = 156.
This method will be more easy.
Parthkushte said:
1 decade ago
Whenever a sq.rt. ends with "25"(1.56'25'), the last digit of root is always "5"(1.25).
The other 'digits can be found by this method: '12'X'13' = '156('1.56'25).
The other 'digits can be found by this method: '12'X'13' = '156('1.56'25).
Oshin said:
1 decade ago
Ya its 1.25, one method is.
Take last 2 digits 25, and square root of it is 5.
And 156 = 12*13, we must take smaller number, 12.
So its 125 and add decimal, then its 1.25.
Take last 2 digits 25, and square root of it is 5.
And 156 = 12*13, we must take smaller number, 12.
So its 125 and add decimal, then its 1.25.
Som said:
10 years ago
Remember trick, in 15625 last two digits can be obtained by multiplying 5*5. Now 156 can be obtained by multi 12*13. So answer will be 125 now put decimal accordingly.
Sidhu said:
8 years ago
@ALL.
Very simple short cut
1+5+6+2+5 = 8
[A]. 1.05(1+5)=6.
[B]. 1.25 (1+2+5)=8.
[C]. 1.45(1+4+5=10)=(1+0)=1.
[D]. 1.55(1+5+5=11)=(1+1)=)2.
So the answer is B.
Very simple short cut
1+5+6+2+5 = 8
[A]. 1.05(1+5)=6.
[B]. 1.25 (1+2+5)=8.
[C]. 1.45(1+4+5=10)=(1+0)=1.
[D]. 1.55(1+5+5=11)=(1+1)=)2.
So the answer is B.
(1)
Shali said:
1 decade ago
5 | 15625
----------
5 | 3125
----------
25| 625
----------
25| 25
----------
| 1
5*5*25*25 while taking square root 5*25 = 125 i.e 1.25 decimal after 2 digits.
----------
5 | 3125
----------
25| 625
----------
25| 25
----------
| 1
5*5*25*25 while taking square root 5*25 = 125 i.e 1.25 decimal after 2 digits.
Sakshi said:
1 decade ago
Hi Shri! 5 power of 6 and 10 power of 4
we can write it= 5 square*5 square*5 square/10 square*10 square under root
it will bcome 5*5*5/10*10 =125/100 =1.25
we can write it= 5 square*5 square*5 square/10 square*10 square under root
it will bcome 5*5*5/10*10 =125/100 =1.25
Dulberg said:
1 decade ago
@Shruti.
I think @Dipankar was just trying to give a clue. Personally I find it very useful. It gives you the idea about the figure you should expect.
I think @Dipankar was just trying to give a clue. Personally I find it very useful. It gives you the idea about the figure you should expect.
Priya said:
1 decade ago
We can write 1.5625 as 15625/10000.
So, (125)^2=15625 and (100)^2=10000.
So, by taking square root of this it became 125/100 So the answer is 1.25.
So, (125)^2=15625 and (100)^2=10000.
So, by taking square root of this it became 125/100 So the answer is 1.25.
Post your comments here:
Quick links
Quantitative Aptitude
Verbal (English)
Reasoning
Programming
Interview
Placement Papers