# 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:

91 comments Page 1 of 10.
Aruna said:
6 months ago

Numbers from 1 to 70.

Having 1 or 9 in unit digits,

1 seven times and 9 seven times,

14/70 * 100 = 20.

Having 1 or 9 in unit digits,

1 seven times and 9 seven times,

14/70 * 100 = 20.

(7)

Moses Ug said:
9 months ago

Does 12 up to 18 have a digit 1 or not?

Anyone, please clarify.

Anyone, please clarify.

(14)

Rasheed nasar said:
1 year ago

Very helpful explanation, Thanks. @Tabi.

(1)

Nikhil said:
2 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.

(14)

LOBSANG said:
2 years ago

Then why don't we consider 7 here because it also ends with 9 as a unit digit 7*7=49?

Anyone clarify it.

Anyone clarify it.

(1)

Manjunath Halageri said:
2 years ago

I think the total numbers are 15 because here, the number 10 is missed.

10 also have the number 1.

10 also have the number 1.

(4)

Shivam Tripathi said:
3 years ago

There are 10 digits from 0 to 9 total( 10 nos) out of which 1 and 9 are asked in question (2 digits) so in question at units place Bo's are not repeating.

Hence 2 digits out of 10 digits Make it 20%(2/10=20%).

Am I right?

Hence 2 digits out of 10 digits Make it 20%(2/10=20%).

Am I right?

(2)

Aditya Singh Shishodia said:
3 years ago

@All.

Unit place is the first digit and not the last. As per the place value system it would always begin from left to right. This is simply a wrongly phrased question.

Unit place is the first digit and not the last. As per the place value system it would always begin from left to right. This is simply a wrongly phrased question.

(2)

Villan said:
3 years ago

The simplest method is by counting the unit places as 3 and 7.

So, there are 14 nos.

14/70*100=20 %.

So, there are 14 nos.

14/70*100=20 %.

Arushi said:
3 years ago

@Jim.

The unit digit is the ending digit.

The unit digit is the ending digit.

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