Four Trees, Three Fall

Probability Level 1

In counting the numbers from 1 to 99 (inclusive), what is the total number of times that the digit 3 is used?

Details and assumptions

The number $12$ uses the digit 1 once and the digit 2 once.

The number $111$ uses the digit 1 three times.

2 solutions

Rathan Srinivas
Aug 6, 2013

first 3,13,23,30,31,32,33,34,35,36,37,38,39,43,53,63,73,83,93, therfore 3 is used 20times 20 is the answer

the answer should be 19...3,13,23,30,31,32,33,34,35,36,37,38,39,43,53,63,73,83,93.. Do you have problem counting numbers???

Francis Almanon - 7 years, 10 months ago

see 33....

Kushaagra Goyal - 7 years, 10 months ago

How ? it must be 19

Ahmed Reda - 7 years, 10 months ago

30 to 39 we have 11 times the digit 3 with "33" have 2 times the digit 3. 1 to 99 except "30 to 39", 3 is used 9 times. So 11+9=20

Retno Setya Rini - 7 years, 10 months ago

Tehreem Fatima
Mar 27, 2019

3, 13, 23, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 43, 53,63, 73, 83,93 So,3 is used 20 times .