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 6 of 11.
Manisha said:
8 years ago
What percentage of numbers from 1 to 90 has a 1 or 9 as one of the digits?
Can anyone solve this?
Can anyone solve this?
Ayas Kanta said:
8 years ago
Can anyone help me to solve this?
A seller got 5% commission on selling for Rs. 10000 and above he got 4% commission. One day he deposited Rs. 31100 in a company after deduction his commission then on that day what was the sale amount?
A seller got 5% commission on selling for Rs. 10000 and above he got 4% commission. One day he deposited Rs. 31100 in a company after deduction his commission then on that day what was the sale amount?
Mustafa said:
8 years ago
Why 12, 13, 14, 15, 16, 17, 18 are not included?
Panda said:
8 years ago
Why 1s of 12, 13,14...,18 is not calculated? Please explain.
Ramesh kannan said:
8 years ago
Very easy 100 ÷ 0 = 1.4285714286.
Next 1.4285714286 * 14 = 20.
Next 1.4285714286 * 14 = 20.
Kamall Barik said:
8 years ago
Thanks for your shortcut @Syed.
Elly said:
9 years ago
@All.
This question has been tricky to understand but thanks to the various explanations. I've got it.
This question has been tricky to understand but thanks to the various explanations. I've got it.
Arjun said:
9 years ago
Please explain, what is unit digit?
Rishav said:
9 years ago
Why you put 11 21 31and all?
Sarika said:
9 years ago
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.
I.E.
100% -------> 70 number.
X --------> 14.
(100x14) / 70 = 20%.
Number of such number = 14.
I.E.
100% -------> 70 number.
X --------> 14.
(100x14) / 70 = 20%.
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