The answer is 66.75
I would suggest multiplying 2 in (2x+1) by 2 5/8 first, then multipling 4 by 2 5/8. This will garner you 10 and 5.25. Distribute the 9 into the (). You'll then get 10.5+47.25+9
Add and you will get 66.75
Each question is either true or false, so the sample space is 2, true and false, two states only.
what's the probability she got one correct, well, the favorable outcomes is 1, possible outcomes is 2, so 1/2.
what's the probability that she got all four correct, we simply multiply the probability of each,
Answers in Image attached
Hope this helps
(20+4)x4 multiply 4x20=80 and 4x4=16. Add 80+16 and get 96.