Aptitude - Percentage - Discussion
Discussion Forum : Percentage - General Questions (Q.No. 4)
4.
What percentage of numbers from 1 to 70 have 1 or 9 in the unit's digit?
Answer: Option
Explanation:
Clearly, the numbers which have 1 or 9 in the unit's digit, have squares that end in the digit 1. Such numbers from 1 to 70 are 1, 9, 11, 19, 21, 29, 31, 39, 41, 49, 51, 59, 61, 69.
Number of such number =14
 Required percentage = |
 |
14 | x 100 |  % = 20%. |
| 70 |
Video Explanation: https://youtu.be/cBamI6iRNIA
Discussion:
102 comments Page 7 of 11.
Shaunak said:
8 years ago
How did we get?
Subash said:
7 years ago
Thank you @Manisha.
Achyuth said:
7 years ago
Let's take 100% for all 10numbers placed in the unit digit. Now 2 numbers(1 or 9) it is 20%.
Laxman said:
7 years ago
In question there should be 1 & 9 instead of 1 or 9.
(1)
Abhishek said:
7 years ago
@All.
If we increase the parameter from 70 to 100 then what?
I mean if we count from 1 to 100 than what will be the solution?
If we increase the parameter from 70 to 100 then what?
I mean if we count from 1 to 100 than what will be the solution?
Abhishek said:
7 years ago
If we count without unit digit. What is the answer?
Puja said:
7 years ago
The Units digit is the digit in the one's column.
Ex-4567, 876, 53.
Unit digit 7,6, 3.
Now come to solution;
1to 70 unit digits are 1,9,11,19,21,29,31,39,41,49,51,59,61,69 =14.
So percentage =14/70*100= 20%.
Ex-4567, 876, 53.
Unit digit 7,6, 3.
Now come to solution;
1to 70 unit digits are 1,9,11,19,21,29,31,39,41,49,51,59,61,69 =14.
So percentage =14/70*100= 20%.
Annu said:
7 years ago
The total number is 70.
Possible values in number.14.
14 is what % of 70.
(14*100)/70.
=20.
Possible values in number.14.
14 is what % of 70.
(14*100)/70.
=20.
Ganesh said:
7 years ago
Simple 1 or 9 in unit digit in 1st 10 no. Is 2,
So 1 to 70 = 2*7 = 14.
% = 14/70*100 = 20% Answer.
So 1 to 70 = 2*7 = 14.
% = 14/70*100 = 20% Answer.
(1)
Sanjana said:
7 years ago
Digits with 1 in unitary place:7.
Digits with 9 in unitary place:7.
7+7=14,
The total numbers=70.
14/70*100=140/7=20%.
Digits with 9 in unitary place:7.
7+7=14,
The total numbers=70.
14/70*100=140/7=20%.
(1)
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