Answer: C and D.
Step-by-step explanation: The pictures show the work. So sorry about the delay -- my computer wasn't letting me type formulas, so I hand-wrote. If you have questions, let me know and I'd be happy to clarify, and if the pictures are sideways, use the rotate button at the top right.
Answer:
Step-by-step explanation:
Total students = 6 + 6 +8 + 4 + 2 +3 + 7 + 5 = 41
Probability of a chosen student be Physics or Chemistry or both =

The total would be 5 13/20 or 113/20
Answer:
128/7 or 18 2/7
Step-by-step explanation:
the decimal answer is 18.28571428... so if you round it, it is 18.3