How to resize images on sequential functions?

I am trying to: - change the format of my images, - then resize their height and width of 40% - then optimize their quality to 35% max of the source and the total size of the image to 35% of the origin. Here my code: find . -name '*.png' -exec mogrify -format jpg {} + && find . -name '*.{jpeg,jpg}' -exec convert -resize 40% _resized.jpg {} + && find ./*.{jpeg,jpg} -exec jpegoptim -m 35% --size=35% {} \; The resizing -line 2- seems to fail. When I am looking at image property I am getting the same image dimensions. I expect that the new image: - is resized - have the original name + the "resized" word at the end of the name