Electrical – Solving 5 variables Karnaugh map – grouping with hazard

Assuming that \$\Phi\$ is the same as X (don't care), I would make the following corrections:

JA = ¬B ¬C ¬D
Here you covered a 0 that you shouldn't, so you have to make a smaller minterm.

KA = D
Here you can make a bigger minterm because the 2*2 are above the minterm only contains don't cares.

KC = ¬D
Again, you can meg a bigger minterm. You don't have to add C because the first column only contains don't cares and ¬D covers the first and the last column.

If we look at the top left corner, where a=0 and c=0, we see that s follows b. This gives us a partial result of s=b. Moving down to the bottom left corner, we see that s is inverted when a=1. This is the XOR operation, and gives us s=a^b. Moving over to the right side, we see that the output is inverted when c=1. This gives us our final result of s=a^b^c.