Question

what is the probability that one number picked from a set of 2 digit number is one digit thrice the other

Answer 1

Total number of digit numbers is 90 [10 to 99]

Total number of two digit number where one digit is thrice the other is 6 {13,26,39,93,62,31}

Probability =6/90=1/15

Answer 2

total nos. from 10 to 99=90

total 2 digit nos. where one digit is thrice the other=6 {13,26,39,93,62,31}

probability= 6/90 =1/15