Error 500 on Wordpress (Magento Integration)

Question

I'm using Magento 1.9 and have installed wordpress in root/blog folder. Here is how my htaccess file looks like. I see an error 500 on blog. Magento site works well though.

# BEGIN WordPress
<IfModule mod_rewrite.c>
RewriteEngine On
RewriteBase /blog/
RewriteRule ^index\.php$ - [L]
RewriteCond %{REQUEST_FILENAME} !-f
RewriteCond %{REQUEST_FILENAME} !-d
RewriteRule . /blog/index.php [L]
</IfModule>

# END WordPress

Answer 1

I don't know if this is the right way

But setting up permissions did the job.

 7       5    5
 user   group  world
 r+w+x  r+x    r+x
 4+2+1  4+0+1  4+0+1 = 755