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?
1
14
20
21
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:
107 comments Page 5 of 11.

Puja said:   8 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%.

Abhishek said:   8 years ago
If we count without unit digit. What is the answer?

Abhishek said:   8 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?

Laxman said:   8 years ago
In question there should be 1 & 9 instead of 1 or 9.
(1)

Achyuth said:   8 years ago
Let's take 100% for all 10numbers placed in the unit digit. Now 2 numbers(1 or 9) it is 20%.

Subash said:   8 years ago
Thank you @Manisha.

Shaunak said:   9 years ago
How did we get?

Daniel said:   9 years ago
Hey, 10, 11, 12, 13, 14, 15, 16, 17, 18 not count?

It have component number 1 too.

Aditys said:   9 years ago
The question should be 1 and 9 not 1 or 9.

Faraz said:   9 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%.


Post your comments here:

Your comments will be displayed after verification.