Question

Question # 37

What percentage of numbers from 1 to 80 have 2 or 3 in the unit's digit?
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Answer 1

Answer:

7 numbers are having 3 in their units place between 1 to 8

Answer 2

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The numbers from 1 to 80 have 1 or 8 in the units places are as under:

1, 8, 11, 18, 21, 28, 31, 38, 41, 48, 51, 58, 61, 68, 71, 78.

The above numbers show a pattern that :

1 to 10 has 2 in Nos,

11 to 20 ….2 in Nos,

21 to 30….2 in Nos……..And so on upto 80. The total in 8 steps upto 80 had 8*2=16 Nos with 1 & 8 in units places. 2 numbers in every 10, In formulae :

(n/10)*2 or 80/10*2=16

Out of 80 numbers 16 are the units of 1,8.

Therefore the percentage is : ( 16/80 )*100= 1/5*100 or 100/5=20%

20% is the answer