Iwill select a brainiest, like and give 20 points to the first person to awnser my questions.
with the first and the two last questions.

23.) 21 hrs at $ 11 per hr = (21 * 11) = 231and u received 91% of ur wages...
       0.91 (231) = 210.21 
       fraction u got : 210.21 / 231 = 0.91 = 91/100 <== I am not 100% sure on 
       this. I might be making this harder then it looksu r going to get 210.31 take home payor 91% which in fraction form is 91/100

26B.  17/10 = 85/ x
          cross multiply
          17x = 850
          x = 850/17
          x = 5050 liters of oil <==

26C. 12:9...added = 21

         12/21(4200) = 50400/21 = 2400 <== higher cost receives 2400
          9/21(4200) = 37800/21 = 1800

Ithink the answer is: it is likely.