1. Discrete Math question

Can someone confirm if this is done correctly?

I dont know if my justification is good enough.

2. Re: Discrete Math question

Originally Posted by inayat

Can someone confirm if this is done correctly?\
I dont know if my justification is good enough.
Correct! Well done.

3. Re: Discrete Math question

$|A \cup B| = |A|+|B| - |A \cap B|$

$|\text{combinatorics or algebra}]| = |\text{combinatorics}|+|\text{algebra}| - |\text{combinatorics and algebra}| = 75 + 60 - 25 = 110$

$P[\text{combinatorics or algebra}] = \dfrac{110}{150} = \dfrac{11}{15}$

$\text{neither combinatorics nor algebra} = \neg \text{combinatorics} \cap \neg \text{algebra}$

$|\neg \text{combinatorics} \cup \neg \text{algebra}| = 150 - |\text{combinatorics or algebra}| = 150 - 110 = 40$

$P[\text{neither combinatorics nor algebra}] = \dfrac{40}{150} = \dfrac{4}{15}$

Looks like you did it correctly. Well done!