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 9 of 11.
Abba said:
8 years ago
What about 11, 12, 13, 14, 15, 16, 17, and 18?
Renukanth said:
8 years ago
What is the need for squaring here, they just asked to find out how man number are there, with the unit digit (1 and 9)?
Faraz said:
8 years ago
It is very simple.
Now there are 14 numbers which start from 1 or 9 It means 14 out of 70.
Now take percentage of 14 out of 70 means multiply by 100 which is equal to 20%.
Now there are 14 numbers which start from 1 or 9 It means 14 out of 70.
Now take percentage of 14 out of 70 means multiply by 100 which is equal to 20%.
Aditys said:
8 years ago
The question should be 1 and 9 not 1 or 9.
Daniel said:
8 years ago
Hey, 10, 11, 12, 13, 14, 15, 16, 17, 18 not count?
It have component number 1 too.
It have component number 1 too.
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%.
Abhishek said:
7 years ago
If we count without unit digit. What is the answer?
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?
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