21 is based on your answer that you already have on the sheet
98⅔ is simply 98 + ⅔, now, how much is ⅔?
well, to convert any fraction to decimal, recall that a/b is just a ÷ b, so ⅔ is just 2 ÷ 3, or 0.6666.....
so 98 + ⅔is then 98 + 0.66666... or just 98.67 rounded up.
You would start with 11.93 times .75, which would round to 8.95. Add that to 11.93 times 2, your answer would be 32.81
