5/4*4/13=20/182=10/91 you take the red marble out so you -1 from the red and the total bag of marbles then you multiply them to gather to get the combined average then simplify
5/12=10/24 and 7/8= 21/24, add those and you will get 31/24 subtract 31 from24 and get 7 your new fraction is 1 7/24 that is 5/12 + 7/8 in simplest form
