Thanks for your feedback @mikoMK. I have made changes according to the suggestion provided by you. I also came to know I have pasted task 2 link wrong, so here is the updated link for task 2-https://jsfiddle.net/shivani0005/f8j20pbs/18/
For task 3 be aware that a mime type may also include some lesser used file extensions. For example image/jpeg also includes .jpe, but I would say most of the time this isn’t really relevant.