The older two-stroke engines DO require mixed gas and oil, but the newer four-stroke engines use separate gas and oil. Which do you have?
98 is an integer and there is no sensible way of representing it as a mixed fraction.
5 and 98/100
98 75/100
98.6 = 98 3/5
98.651 = 98 651/1000
98/7
71 and 98/100
the solar nebula was 98% hydrogen and helium gas
98 and 3/5
8 and 10/11
3.98 = 3 and 98/100 = 3 and 49/50
98/11 is already a fraction in simplest form. As a mixed number it is 810/11