Having Trouble on Web development 1 level 12

can any anyone help me with this code?

/* Add a rule for #element3 */

    /* Change #element3's b

Please I am dying over here

You have to use HTML

Thank you for helping, but please could you not post on a topic which is more than 6 months old, or where the user is inactive. You can tell this by going to their profile page and seeing when they were seen last. This person was last seen in Jan. 2018 so I don’t think they’re going to see your post.
Thanks,
Danny