Answer: 7/6
The ratio of 3.5 years to 3 years can be written as a fraction 3.5/3. To express this with whole numbers in the numerator, we can multiply both the numerator and the denominator by 2 (to eliminate the decimal), which gives us 7/6
So, the ratio of 3.5 years to 3 years in simplest form, with whole numbers in the numerator, is 7/6.