What percentage of numbers from 1 to 50 has 3 or 7 in the unit's digit?

Question: What percentage of numbers from 1 to 50 has 3 or 7 in the unit's digit?Solution:We can list the numbers from 1 to 50 and identify those that have 3 or 7 in the unit's place:Numbers with 3 in the unit's digit:3, 13, 23, 33, 43Numbers with 7 in the unit's digit: 7, 17, 27, 37, 47So, the numbers with 3 or 7 in the unit's digit are:3, 7, 13, 17, 23, 27, 33, 37, 43, 47There are 10 such numbers.There are 50 numbers in total from 1 to 50. The percentage of numbers that have 3 or 7 in the unit's digit is: (10/50) × 100%= 20%