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 3 of 11.
Syed Rasheed said:
6 months ago
1-10 = 2 available 1,9.
11-20 = 2 available 11,19.
21-30 = 2 available 21,29.
31-40 = 2 available 31,39.
41-50 = 2 available 41,49.
51-60 = 2 available 51,59.
61-70 = 2 available 61,69.
Q1/q2 ×100.
= 14/70 ×100
= 20.
11-20 = 2 available 11,19.
21-30 = 2 available 21,29.
31-40 = 2 available 31,39.
41-50 = 2 available 41,49.
51-60 = 2 available 51,59.
61-70 = 2 available 61,69.
Q1/q2 ×100.
= 14/70 ×100
= 20.
(10)
Nikhil said:
3 years ago
@Lobsang.
Because, They didn't ask about us anyone's Square.
They just told you to find how many no belongs in 1to70 That last digit should come only 1 and 9. Like 01, 09, 11, 19, 21, 29. 69.
Hope you understood.
Because, They didn't ask about us anyone's Square.
They just told you to find how many no belongs in 1to70 That last digit should come only 1 and 9. Like 01, 09, 11, 19, 21, 29. 69.
Hope you understood.
(19)
PANKAJ said:
1 decade ago
@ ROSS
The no 10 after squaring it does not end with 1.......
if u square to 1,11,19,21 it ends with 1
Squaring 10 = 10 x 10 = 100 it ends with 0
Squaring 11 = 11 x 11 = 121 it ends with 1
I think u got it.
The no 10 after squaring it does not end with 1.......
if u square to 1,11,19,21 it ends with 1
Squaring 10 = 10 x 10 = 100 it ends with 0
Squaring 11 = 11 x 11 = 121 it ends with 1
I think u got it.
Zaman said:
1 decade ago
We should first understand the question ?
The question asks the numbers with 1 or 9 in the unit digit that is in the last digit or ending with 1 or 9.
12, 13, 14 have 2, 3 and 4 in the unit digit respectively.
The question asks the numbers with 1 or 9 in the unit digit that is in the last digit or ending with 1 or 9.
12, 13, 14 have 2, 3 and 4 in the unit digit respectively.
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%.
Daniel said:
1 decade ago
The question doesn't specify that the digits 1 or 9 must be the last digits, so clearly all the number in the teens, would qualitfy as nubers between 1 and 70 that have the digit 1 OR 9.
Uttam said:
1 decade ago
Inside the 10 there are 2 digits which ends with 1 and 9.
Number 70 consists 7 tens.
So total no of digits that end with 1 and 9 in 70 are,
7*2=14.
So percentage= (14/70) *100=20.
Number 70 consists 7 tens.
So total no of digits that end with 1 and 9 in 70 are,
7*2=14.
So percentage= (14/70) *100=20.
Narendra said:
6 years ago
I don't understand about value of 14. In question they asking 1 or 9 but not 1&9. They asked about 1 or 9 so how could you consider as 14? Please explain clearly to understand.
Nicky said:
1 decade ago
In question he said 1 or 9 in the units digit there are 4 numbers between 1 to 10 whose unit digit ends between 1 and 9 they are 1, 3, 7, 9 so tell me that what is the solution?
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%.
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