4 Mary saves her digital images on her computer in three separate folders named 'Family', 'Holiday' and 'Friends'. Her family folder contains 3 images, her holiday folder contains 4 images and her friends folder contains 8 images. All the images are different.

1. Find in how many ways she can arrange these 15 images in a row across her computer screen if she keeps the images from each folder together.
2. Find the number of different ways in which Mary can choose 6 of these images if there are 2 from each folder.
3. Find the number of different ways in which Mary can choose 6 of these images if there are at least 3 images from the friends folder and at least 1 image from each of the other two folders.