Another method

Let’s count the numbers from 1 to 70 that have 1 or 9 in the unit’s digit:

Numbers with 1 in the unit’s digit: 1, 11, 21, 31, 41, 51, 61

Numbers with 9 in the unit’s digit: 9, 19, 29, 39, 49, 59, 69

There are 7 numbers with 1 in the unit’s digit and 7 numbers with 9 in the unit’s digit, making a total of 14 numbers.

To find the percentage:

(14/70) × 100 = 20%

So, 20% of numbers from 1 to 70 have 1 or 9 in the unit’s digit.